Patent Grant
11688920
The present disclosure is a national stage application of International Patent Application No. PCT/CN2018/125166, which is filed on Dec. 29, 2018 and claims priority to Chinese Patent Priority No. 201811155049.9, filed to the National Intellectual Property Administration, PRC on Sep. 30, 2018, entitled “Concave Triple-Mode Cavity Resonance Structure and Filter with the Resonance Structure”, the disclosure of which is hereby incorporated by reference in its entirety.
The disclosure relates to a base station filter, an antenna feeder filter, a combiner, an anti-interference filter and the like used in the field of wireless communications. Types of the filters may be band pass, band stop, high pass and low pass, and the disclosure particularly relates to a concave triple-mode cavity resonance structure and a filter with the concave triple-mode cavity resonance structure.
Along with the rapid development of 4G mobile communications to 5G mobile communications, miniaturization and high performance of communication facilities are increasingly highly required. Traditional filters are gradually replaced by single-mode dielectric filters due to large metallic cavity volume and ordinary performance, the single-mode dielectric filters mainly include a Transverse Electric 01 (TE01)-mode dielectric filter and a Transverse Magnetic (TM)-mode dielectric filter, the TE01-mode dielectric filter and the TM-mode dielectric filter generally adopt a single-mode dielectric resonant mode, and the resonant mode increases a certain Q value, but has defects of high manufacturing cost and large volume.
In order to solve technical problems of high cost and large volume of the single-mode dielectric filters, a triple-mode dielectric filter emerges at the right moment. In an art known to inventors, the triple-dielectric filter generally includes a TE triple-mode filter and a TM triple-mode filter. The TE triple-mode filter has the characteristics of being complex in coupling mode, large in volume and high in Q value, and the TM triple-mode filter has the characteristics of being simple in coupling mode, small in volume and low in Q value. With respect to a TE triple-mode filter and a TM triple-mode filter of a same frequency band, the weight, cost and volume of the TM triple-mode filter are greatly smaller than those of the TE triple-mode filter. Therefore, in the art known to inventors, the TE triple-mode filter is generally adopted to design a narrow band filter, and the TM triple-mode filter is generally used as other types of filters. Since a dielectric resonant block of the TM triple-mode filter is coated by baked silver, a vitreous substance is formed between a silver layer after silver baking and a surface of the dielectric resonant block, thus actual conductivity is greatly degraded, the Q value is actually low, and the use range of the TM triple-mode filter is further limited. Therefore, how to obtain a TM triple-mode filter of a small volume and a high Q value is a new direction of research and development of filters.
The TM triple-mode filter known to inventors generally adopts a structure that, a cube/cube-like/spherical dielectric resonant block is arranged in a cube/cube-like/spherical resonant cavity, the dielectric resonant block is supported by a dielectric base, and a ratio of a size of a single side of the resonant cavity to a size of a single side of the dielectric resonant block is generally greater than 1.6. When the volume of the resonant cavity is maintained and the volume of the dielectric resonant block is slightly increased, or the volume of the resonant cavity is slightly decreased and the volume of the dielectric resonant block is maintained, or the volume of the resonant cavity is slightly decreased and the volume of the dielectric resonant block is slightly increased, comparison of data provided by Table 1 shows that while the ratio of the size of the single side of the resonant cavity to the size of the single side of the dielectric resonant block is increased, a Q value of a base mode is increased along with increase of the ratio, a Q value of a higher-order mode is decreased along with increase of the ratio, the size of the dielectric resonant block is decreased along with increase of the ratio, the size of a cavity is continuously increased, when the size is approximate to a ¾ wavelength size of the cavity, the size of the dielectric resonant block is continuously decreased, the Q value of the base mode is also decreased, and a frequency of the higher-order mode is approximate to or far away from a frequency of the base mode along with increase of the ratio at times.
Cavity volumes of the resonant cavities corresponding to different ratios are also different and can be selected according to actual demands. Single cavities with a ratio of 1.6 or greater may be selected for cavities of different sizes in a ratio range in Table 1 and corresponding cube-like dielectric resonant block when the performance requirement of filters is higher. Therefore, when the ratio of the size of the single side of the resonant cavity to the size of the single side of the dielectric resonant block is greater than 1.6, the Q value is proportional to a distance between the resonant cavity and the dielectric resonant block, but a defect that the volume of a filter is too large is caused.
The patent known to inventors, discloses a triple-mode cavity structure with a small volume and a high Q value, and the structure ensures that the volume of a filter is effectively decreased and a Q value is increased while an outer surface of a dielectric resonant block and an inner surface of a cavity are arranged in parallel and the distance between the two surfaces is very small. However, such structure has the following technical problems: 1. Due to the very small distance between the dielectric resonant block and an inner wall of the cavity, the tuning range of a tuning screw is limited, and installation and debugging of the dielectric resonant block are obstructed; 2. Due to the very small distance between the dielectric resonant block and the inner wall of the cavity, the distance between the dielectric resonant block and the cavity is very sensitive to a single cavity resonant frequency, and thus on-batch production of the dielectric resonant block is obstructed; and 3. Since the very small distance between the dielectric resonant block and the inner wall of the cavity is very sensitive to the single cavity resonant frequency, the design precision of the dielectric resonant block and the cavity is highly required, and thus the processing and manufacturing cost is increased.
In light of the defects of an art known to inventors, the disclosure aims to solve a technical problem of providing a concave triple-mode cavity resonance structure and a filter with the resonance structure, and the structure is capable of reducing overall insertion loss, of the filter to meet requirements of a cavity filter on small insert and smaller volume.
The disclosure discloses a concave triple-mode cavity resonance structure which includes a cavity and a cover plate, wherein the cavity is internally provided with a dielectric resonant block and a dielectric support frame; the cavity takes a cube-like shape; the dielectric resonant block takes a cube-like shape and at least one end face is concave; the dielectric support frame is connected with the dielectric resonant block and an inner wall of the cavity, respectively; the dielectric resonant block and the dielectric support frame form a triple-mode dielectric resonator; a dielectric constant of the dielectric support frame is smaller than a dielectric constant of the dielectric resonant block; when a ratio K of the size of a single side of the inner wall of the cavity to the size of a single side of the dielectric resonant block is: when K is greater than or equal to a transition point 1 and is smaller than or equal to a transition point 2, a Q value of a higher-order mode adjacent to a base mode is transited into a Q value of the base mode of the triple-mode cavity resonant structure, a base-mode resonant frequency after transition is equal to a base-mode resonant frequency prior to transition, a Q value of the base mode after transition is greater than a Q value of the base mode prior to transition, and a Q value of the higher-order mode adjacent to the base mode after transition is smaller than a Q value of the higher-order mode is adjacent to the base mode prior to transition; the triple-mode dielectric resonant structure is internally provided with a coupling structure for changing orthogonal properties of a degenerate triple-mode electromagnetic field in the cavity; and the triple-mode dielectric resonant structure is internally provided with a frequency tuning device for changing degenerate triple-mode resonant frequencies in the cavity.
In an exemplary embodiment of the disclosure, the concave triple-mode cavity resonant structure includes a cavity and a cover plate, wherein the cavity is internally provided with a dielectric resonant block and a dielectric support frame; the cavity takes a cube-like shape and at least one end face is concave; the dielectric resonant block takes a cube-like shape; the dielectric support frame is connected with the dielectric resonant block and an inner wall of the cavity, respectively; the dielectric resonant block and the dielectric support frame form a triple-mode dielectric resonator; a dielectric constant of the dielectric support frame is smaller than a dielectric constant of the dielectric resonant block; when a ratio K of the size of a single side of the inner wall of the cavity to the size of a single side of the dielectric resonant block is: when K is greater than or equal to a transition point 1 and is smaller than or equal to a transition point 2, a Q value of a higher-order mode adjacent to a base mode is transited into a Q value of the base mode of the triple-mode cavity resonant structure, a base-mode resonant frequency after transition is equal to a base-mode resonant frequency prior to transition, a Q value of the base mode after transition is greater than a Q value of the base mode prior to transition, and a Q value of the higher-order mode adjacent to the base mode after transition is, smaller than a Q value of the higher-order mode adjacent to the base mode prior to transition; the triple-mode dielectric resonant structure is internally provided with a coupling structure for changing orthogonal properties of a degenerate triple-mode electromagnetic field in the cavity; and the triple-mode dielectric resonant structure is internally provided with a frequency tuning device for changing degenerate triple-mode resonant frequencies in the cavity.
In an exemplary embodiment of the disclosure, the concave triple-mode cavity resonance structure includes a cavity and, a cover plate, wherein the cavity is internally provided with a dielectric resonant block and a dielectric support frame; the cavity takes a cube-like shape and at least one end face is concave; the dielectric resonant block takes a cube-like shape and at least one end face is concave; the dielectric support frame is connected with the dielectric resonant block and an inner wall of the cavity, respectively; the dielectric resonant block and the dielectric support frame form a triple-mode dielectric resonator; a dielectric constant of the dielectric support frame is smaller than a dielectric constant of the dielectric resonant block; when a ratio K of the size of a single side of the inner wall of the cavity to the size of a single side of the dielectric resonant block is; when K is greater than or equal to a transition point 1 and is smaller than or equal to a transition point 2, a Q value of a higher-order mode adjacent to a base mode is transited into a Q value of the base mode of the triple-mode dielectric resonant structure, a base-mode resonant frequency after transition is equal to a base-mode resonant frequency prior to transition, a Q value of the base mode after transition is greater than a Q value of the base mode prior to transition, and a Q value of the higher-order mode adjacent to the base mode after transition is smaller than a Q value of the higher-order mode adjacent to the base mode prior to transition; the triple-mode, dielectric resonant structure is internally provided with a coupling structure for changing orthogonal properties of a degenerate triple-mode electromagnetic field in the cavity; and the triple-mode dielectric resonant structure is internally provided with a frequency tuning device for changing degenerate triple-mode resonant frequencies in the cavity.
In an exemplary embodiment of the disclosure, the dielectric resonant block is of a solid structure or hollow structure, a hollow part of the dielectric resonant block of the hollow structure is filled with air or a nested dielectric resonant block, and a volume of the nested dielectric resonant block is smaller than or equal to a volume of a hollow chamber.
In an exemplary embodiment of the disclosure, the nested dielectric resonant block takes a cube-like shape and at least one end face is concave.
In an exemplary embodiment of the disclosure, a film dielectric is arranged on at least one end face of the nested dielectric resonant block.
In an exemplary embodiment of the disclosure, a film dielectric is arranged on at least one end face of the cavity or/and at least one end face of the dielectric resonant block.
In an exemplary embodiment of the disclosure, a value of the transition point 1 and a K value of the transition point 2 both vary according to different base-mode, resonant frequencies of the dielectric resonant block, dielectric constants of the dielectric resonant block and dielectric constants of the support frame.
In an exemplary embodiment of the disclosure, when the base-mode resonant frequency of the dielectric resonant block after transition remains unchanged, the Q value of the triple-mode dielectric resonant structure is relevant to the K value, the dielectric constant of the dielectric resonant block and the size of the dielectric resonant block.
In an exemplary embodiment of the disclosure, when the K value is increased to the maximum from 1.0 the K value has three Q value transition points within a variation range, each Q value transition point enables the Q value of the base mode of the K value and the Q value of the higher-order mode adjacent to the base mode of the K value to be transited; when the Q value of the base mode is lower than the Q value of the higher-order mode adjacent to the base mode, the Q value of the higher-order mode adjacent to the base mode is transited into the Q value of the base mode, and the Q value of the base mode is higher than that prior to transition; and when the Q value, of the base mode is higher than the Q value of the higher-order mode adjacent to the base mode, the Q value of the higher-order mode adjacent to the base mode is transited into the Q value of the base mode, and the Q value of the base mode is lower than that prior to transition.
In an exemplary embodiment of the disclosure, in four areas formed by a start point and a final point of the K value and the three value Q transition points, the Q value of the base mode and the Q value of the higher-order mode adjacent to the base mode vary along with variation of cavity sizes and dielectric resonant block sizes, and different areas have different requirements when being applied to a filter.
In an exemplary embodiment of the disclosure, the value of the transition point 1 is greater than or equal to 1.03 and smaller than or equal to 1.30, the value of the transition point 2 is greater than or equal to 1.03 and smaller than or equal to 1.30, and the value of the transition point 1 is smaller than the value of the transition point 2.
In an exemplary embodiment of the disclosure, the coupling structure is arranged on the dielectric resonant block, and the coupling structure at least includes two nonparallel arranged holes and/or grooves and/or cut corners and/or chamfers.
In an exemplary embodiment of the disclosure, the grooves or the cut corners or the chamfers are arranged on edges of the dielectric resonant block.
In an exemplary embodiment of the disclosure, the holes or grooves are arranged on an end face of the dielectric resonant block, central lines of the holes or grooves, are parallel to edges, of end faces in which holes or grooves are formed perpendicularly to the dielectric resonant block.
In an exemplary embodiment of the disclosure, the coupling structure is arranged on the cavity, and the coupling structure at least includes two nonparallel arranged chamfers and/or bosses arranged at inner corners of the cavity and/or tapping lines/pieces arranged in the cavity and do not contact with the dielectric resonant block.
In an exemplary embodiment of the disclosure, a frequency tuning device includes a tuning screw arranged on the cavity and/or a film arranged on the surface of the dielectric resonant block and/or a film arranged on the inner wall of the cavity and/or a film arranged on the inner wall of the cover plate.
In an exemplary embodiment of the disclosure, at least one dielectric support frame is arranged on at least one end face of the dielectric resonant block.
The disclosure also discloses a filter with the concave, triple-mode cavity resonant structure. The filter includes a cavity, a cover plate and an input/output structure, and the cavity is at least internally provided with one concave triple-mode cavity resonant structure.
In an exemplary embodiment of the disclosure, the concave triple-mode cavity resonant structure is combined with a single-mode resonant structure, a dual-mode resonant structure and a triple-mode resonant, structure in different modes to form filters of different volumes; a coupling of any two resonant cavities formed by permutation and combination of the concave triple-mode dielectric resonant structure and any one of the single-mode resonant structure, the dual-mode resonant structure and the triple-mode resonant structure is achieved through a size of a window between the two resonant cavities necessarily when resonant blocks in the two resonant cavities are parallel, and the size of the window is determined according to a coupling amount; and the filter has function properties of band pass, band stop, high pass, low pass and a duplexer, a multiplexer and a combiner formed thereby.
In an exemplary embodiment of the disclosure, when a resonant frequency of the concave triple-mode cavity resonant structure is maintained, a triple-mode value is relevant to the ratio K of the side length of the inner wall of the cavity to the side length of the dielectric resonant block, the dielectric constant of the dielectric resonant block and a size variation range of the dielectric resonant block, and the range of the K value is relevant to different resonant frequencies and dielectric constants of the dielectric resonant block and the dielectric support frame.
In the above technical solution, the variation range of the ratio K of the side length of the inner wall of the cavity in the concave triple-mode cavity resonant structure to the size of the dielectric resonant block is that when the K value is increased to the maximum from 1.0, the K value has three Q value transition points within the variation range, each transition point enables the Q value of the base-mode resonant frequency to be transited into the Q value of an adjacent higher-order mode resonant frequency, and when an adjacent Q value of the higher-order mode, is transited into the Q value of the base mode, the Q value of the base mode and the Q value of the higher-order mode are increased when being compared with that prior to transition (i.e. both the Q value of the base mode and the Q value of the higher-order mode increase with increasing the K value).
In an exemplary embodiment, in four areas formed by the start point and the final point of the K value and the three value Q transition points, the Q value of the base mode and the adjacent Q value of the higher-order mode gradually vary along with variation of cavity sizes and dielectric resonant block sizes, and different areas have different requirements when being applied to the filter (application in different areas is explained in the description and examples).
In an exemplary embodiment, the dielectric resonant block of the disclosure is of a solid structure of a cube-like shape, the cube-like shape is defined as that the dielectric resonant block is a cuboid or cube, when the dielectric resonant block has a same size in X, Y and Z axes, a degenerate triple mode is formed, and the degenerate triple-mode is coupled with other single cavities to form a passband filter; when differences of sizes in three directions along the X, Y and Z axes are slightly unequal, orthogonal-like triple-mode resonant is formed, if an orthogonal-like triple-mode is capable of coupling with other cavities into the passband filter, the sizes are acceptable, and if the orthogonal-like triple-mode cannot be coupled with other cavities into the passband filter, the sizes are unacceptable: and when the differences of the sizes in the three directions along the X, and Z axes are greatly different, the degenerate triple-mode or orthogonal-like triple-mode cannot be formed, three modes of different frequencies are formed instead, thus the modes cannot be coupled with other cavities into the passband filter, and the sizes are unacceptable.
In an exemplary embodiment, the concave triple-mode cavity resonant structure is internally provided with at least two nonparallel arranged coupling devices for changing orthogonal properties of a degenerate triple-mode electromagnetic field in the cavity, each of the coupling devices includes cut corners and/or holes arranged beside edges of the dielectric resonant block, or includes chamfers and/or cut corners arranged beside the edges of the cavity, or includes cut corners and/or holes arranged beside the edges of the dielectric resonant block, and chamfers/cut corners arranged besides the edges of the cavity, or includes tapping lines or/pieces arranged on nonparallel planes in the cavity, the cut corners take a shape of a triangular prism, a cuboid or a sector, the holes take a shape of a circle, a rectangle or a polygon. After corner cutting or hole formation, in case of frequency holding, side lengths of the dielectric resonant block are increased, and the Q value is slightly decreased; depths of the cut corners or holes are of through or partial cut corners/partial hole structures according to required coupling amounts; the coupling amounts are affected by the sizes of the cut corners/chamfers/holes; a coupling tuning structure includes a coupling screw arranged in a direction perpendicular or parallel to the cut corners and/or a direction parallel to the holes; the coupling screw is made of a metal, or the coupling screw is made of a metal and the metal is electroplated by copper or electroplated by silver, or the coupling screw is made of a dielectric, or the coupling screw is made of a surface metallized dielectric; the coupling screw takes a shape of any one of metallic rods, dielectric rods, metallic discs, dielectric discs, metallic, rods with metallic discs, metallic rods with dielectric discs, dielectric discs with metallic discs and dielectric rods with dielectric discs.
In an exemplary embodiment, the concave triple-mode cavity resonant structure forms the degenerate triple-mode in directions along the X, Y and Z axes, and a resonant frequency of the degenerate triple-mode in the direction of an X axis is achieved by additionally installing a tuning screw or a tuning disc at a place with concentrated field, intensity on one or two faces of the X axis corresponding to the cavity so as to change a distance or change capacitance; a resonant frequency in the direction of a Y axis is achieved by additionally installing a tuning screw or a tuning disc at a place with concentrated field intensity on one or two faces of the Y axis corresponding to the cavity so as to change a distance or change capacitance; a resonant frequency in the direction of a Z axis is achieved by additionally installing a tuning screw or a tuning disc at a place with concentrated field intensity on one or two faces of the Z axis corresponding to the cavity so as to change a distance or change capacitance; dielectric constant films of different shapes and thicknesses are adhered to a surface of the dielectric resonant block, the inner wall of the cavity or cover plate and the bottom of the tuning screw, and the films are made of a ceramic dielectric or a ferroelectric material, and frequencies are adjusted by changing dielectric constants; the tuning screw or the tuning disc is made of a metal, or the tuning screw or the tuning disc is made of a metal and the metal is electroplated by copper or electroplated by silver, or the tuning disc or the tuning disc is made of a dielectric, or the tuning screw or the tuning disc is made of a surface metallized dielectric; the tuning screw takes a shape of any one of metallic rods, dielectric rods, metallic discs, dielectric discs, metallic rods with metallic discs, metallic rods with dielectric discs, dielectric discs with metallic discs and dielectric rods with dielectric discs; a frequency temperature coefficient of the dielectric resonant block that takes the cube-like shape is controlled by adjusting proportions of dielectric materials, and is compensated according to frequency deviation variation of the filter at different temperatures; and when the dielectric support frame is fixed with the inner wall of the cavity, in order to avoid stress caused by the cavity and the dielectric materials in a sudden temperature variation environment, an elastomer for transition is adopted therebetween, so that reliability risks, caused by expansion coefficients of materials is buffered.
In an exemplary embodiment, the concave triple-mode dielectric resonant structure includes the cavity, the dielectric resonant block and the support frame; when the cavity takes the cube-like shape, a single cube-like dielectric resonant block and the dielectric support frame are installed in any one axial direction of the cavity, and a center of the dielectric resonant block coincides with or approaches to a center of the cavity. An approximate air dielectric support frame supports with any one single face of a cube-like dielectric block, or supports with six faces, or supports with different combinations of two different faces, three faces, four faces and five faces, the dielectric support frame on each face is one or more dielectric support frames, and one or more support frames are installed on different faces according to demands. A support frame of which the dielectric constant is greater than a dielectric constant of air and smaller than a dielectric constant of the dielectric resonant block to supports with any one single face of the cube-like dielectric block, or supports with six faces, or supports with different combinations of two different faces, three faces, four faces and five faces; a face without the support frame is air; the air face is arbitrarily combined with the dielectric support frame; the dielectric support frame on each face is one or more dielectric support frames, or is a complex dielectric constant support frame composed of multiple layers of different dielectric constant dielectric materials; single-layer and multi-layer dielectric material support frames are arbitrarily combined with cube-like dielectric blocks; one or more support frames are installed on different faces according to demands; on faces with the support frames, to hold the triple-mode frequencies and the Q value, the size corresponding to the axial direction of the dielectric resonant block of the dielectric support frame is slightly reduced; a single face support combination supports any one face of the dielectric resonant block, and particularly an under surface or bearing surface in a vertical direction; a support combination of two faces includes parallel faces such as upper and lower faces, front and rear faces and left and right faces, and also includes nonparallel faces such as upper and front faces, upper and rear faces, upper and left faces and upper and right faces; a support combination of three faces includes three faces perpendicular to one another, or two parallel faces and one nonparallel face; a support combination of four faces includes two pairs of parallel faces or a pair of parallel faces and two another nonparallel faces; a support combination of five faces includes support structures of other faces except any one face of a front face/a rear face/a left face/a right face/an upper face/a lower face; and a support combination of six faces includes support structures of all faces of a front face/a rear face/a left face/a right face/an upper face/a lower face.
In an exemplary embodiment, any end of the cube-like dielectric resonant block and the dielectric support frame are connected in a mode of crimping, adhesion or sintering; connection is one face connection or combined connection of different faces; multi-layer dielectric support frames are fixed in modes of adhesion, sintering, crimping and the like; the dielectric support frame and the inner wall of the cavity are connected in a mode of adhesion, crimping, welding, sintering or screw fixation; a radio frequency channel formed by coupling of radio frequency signals in directions of the X, Y and Z axes of the triple mode causes loss and generates heat, the dielectric resonant block is sufficiently connected with the inner wall of the cavity through the dielectric support frame, and thus the heat is conducted into the cavity for heat dissipation.
In an exemplary embodiment, the cube-like dielectric resonant block has a single dielectric constant or composite dielectric constants; the dielectric resonant block with the composite dielectric constants is formed by at least two materials of different dielectric constants; the materials of different dielectric constants are combined up and down, left and right, asymmetrically or in a nested mode; when the materials of different dielectric constants are nested in the dielectric resonant block, one or more layers are nested; and the dielectric resonant block with the composite dielectric constants needs to comply with variation rules of the Q value transition points. When the dielectric resonant block is subjected to cut side coupling among triple modes, to hold the required frequency, corresponding side lengths of two faces adjacent to the cut sides are adjusted. The dielectric resonant block is made of a ceramic or dielectric material, and dielectric sheets of different thicknesses and different dielectric constants are added on the surface of the dielectric resonant block.
In an exemplary embodiment, the dielectric constant of the dielectric support frame is similar to the air dielectric constant, or the dielectric constant of the support frame is greater than the air dielectric constant or smaller than the dielectric constant of the dielectric resonant block; the surface area of the dielectric support frame is smaller than or equal to that of the dielectric resonant block; and the dielectric support frame takes a shape of a cylinder, a cube or a cuboid. The dielectric support frame is of a solid structure or hollow structure, the dielectric support frame of the hollow structure includes a single hole or multiple holes, the hole takes a shape of a circle, a square, a polygon and an arc; the dielectric support frame is made of air, plastics; ceramics and dielectrics; the dielectric support frame is connected with the dielectric resonant block: when the dielectric constant of the dielectric support is similar to the air dielectric constant, the dielectric support has no effect on the three-mode resonant frequency. when the dielectric constant of the dielectric support frame is greater than the air dielectric constant and smaller than the dielectric constant of the dielectric resonant block, in order to hold original triple-mode frequencies, the size corresponding to the axial direction of the dielectric resonant block of the dielectric support frame is slightly reduced; a support frame with a dielectric constant similar to that of air and a support frame with a dielectric constant smaller than that of the dielectric resonant block are combined and installed in different directions and different corresponding faces of the dielectric resonant block; and when the two support frames of different dielectric constants are combined for use, an axial direction size greater than that of a dielectric resonant block corresponding to an air support frame is slightly reduced on an original basis.
In an exemplary embodiment, the cavity takes the cube-like shape; to achieve coupling of three modes, on premise that the size of the dielectric resonant block is not changed, cut sides for achieving coupling of the three modes are processed on any two adjacent faces of the cavity; the sizes of the cut sides are relevant to required coupling amounts; coupling of two of the three modes is achieved through the cut sides of the cube-like; other coupling is achieved through cut corners of two adjacent sides of the cavity; walls are not broken when corners of the adjacent sides of the cavity are cut; and cut corner faces are completely sealed with the cavity. The cavity is made of a metal or a nonmetal material, the surface of the metal and the nonmetal material is electroplated by copper or silver, and when the cavity is made of the nonmetal material, the inner wall of the cavity needs to be electroplated by a conductive material such as copper or silver, such as plastics and composite materials electroplated by copper or silver.
In an exemplary embodiment, the concave triple-mode dielectric resonant structure is combined with a single-mode resonant structure, a dual-mode resonant structure and a triple-mode resonant structure in different modes to form filters of different volumes; a coupling of any two resonant cavities formed by permutation and combination of the concave triple-mode dielectric resonant structure and any one of the single-mode resonant structure, the dual-mode resonant structure and the triple-mode resonant structure is achieved through a size of a window between the two resonant cavities necessarily when resonant blocks in the two resonant cavities are parallel, and the size of the window is determined according to a coupling amount; and the filter has function properties of band pass, band stop, high pass, low pass and a duplexes, a multiplexer and a combiner formed thereby.
The dielectric constant of the cube-like dielectric resonant block of some embodiments in the disclosure is greater than the dielectric constant of the support frame; when the ratio of the size of the single side of the inner wall of the cavity to the size of the single side of the dielectric resonant block is within 1.03-1.30, the Q value of the higher-order mode is transited into the Q value of the base mode, a triple-mode dielectric Q value of the base mode is increased and the Q value of the higher-order mode is decreased, and compared with single mode and triple-mode dielectric filters known to inventors with same volumes and frequencies, the Q value is increased by 30% or greater; the triple-mode cavity structure is combined with single cavities of different types, for example, the triple-mode cavity structure is combined with a cavity single mode, the triple-mode is combined with the TM mode and the triple-mode is combined with the TE single mode, the greater the number of triple-modes in the filter is the smaller the volume of the filter is, and the smaller the insertion loss is; the concave triple-mode cavity resonant structure generates triple-mode resonance in directions of the X, Y and Z axes, and triple-mode resonance is generated in the directions of the X, Y and Z axes.
When the ratio of the side length of the inner wall of the cavity to the size of a corresponding side length of the dielectric resonance block is within 1.0 to the transition point 1 transited from the Q value, and, when the ratio of 1.0, the cavity has a pure, dielectric Q value, when the size of the cavity is increased, the Q value is continuously increased on the basis of a pure dielectric, the Q value of the higher-order mode is greater than the Q value of the base mode, and when the ratio is increased to the transition point 1, an original Q value of the higher-order mode is approximated to a new Q value of the base mode.
After entering into the transition point 1, in case that the base-mode resonant frequency is maintained, the Q value of the base mode is greater than the Q value of the higher-order mode. Along with increase of the ratio, the sizes of the dielectric block and the cavity are both increased, the Q value of the base mode is also increased, and the Q value of the higher-order mode is also increased; when the ratio is approximate to the transition point 2 of Q value transition, the Q value of the base mode is the highest, between the transition point 1 transited from the Q value of the base mode and the transition point 2 transited from the Q value of the base mode, the frequency of the higher-order mode is approximate to or far away from the frequency of the base mode along with variation of the ratio of the cavity to the dielectric resonant block between the transition point 1 and the transition point 2 at times.
After entering the transition point 2, the Q value of the base mode is smaller than the Q value of the higher-order mode; along with increase of the ratio, the size of the dielectric resonant block is reduced, the size of the cavity is increased, the Q value of the base mode is constantly increased, and when the ratio is approximate to a transition point 3, the Q value of the base mode is approximate to the Q value at the transition point 2.
When the ratio enters the transition point 3, the value of the base mode is increased along with increase of the ratio, the Q value of the higher-order mode is decreased along with increase of the ratio, the size of the dielectric resonant block is decreased along with increase of the ratio, and the size of the cavity is constantly increased; when the size is approximate to a ¾ wavelength size of the cavity, the size of the dielectric resonant block is constantly decreased, the Q value of the base mode is also decreased, and the frequency of the higher-order mode is approximate to or far away from the frequency of the base mode along with increase of the ratio at times. A particular ratio of the size of the transition points is relevant to dielectric constants and frequencies of the dielectric resonant block and single or composite dielectric constants of the dielectric resonant block.
The side, length of the inner wall of the cavity and the side length of the dielectric resonant block may be or may be not equal in three directions of the X, Y and Z axes. The triple mode is formed when the sizes of the cavity and the cube-like dielectric resonant block are equal in the X, Y and Z axes; size differences in three directions of the X, Y and Z axes may also be slightly unequal; when the sizes of single sides of the cavity in one direction of the X, Y and Z axes and the corresponding dielectric resonant block is different from the sizes of single sides in other two directions of the X, Y and Z axes, or any one of the sizes of symmetric single sides of the cavity and the dielectric resonant block are also different from the sizes of single sides in the other two directions, the frequency of one of the triple modes varies and is different from frequencies of the other two modes of the triple modes, and the larger the size difference is, the larger the difference of the frequency of one mode from those of the other two modes is; when the size in one direction is greater than the sizes in the other two directions, the frequency is decreased on an original basis; when the size in one direction is smaller than those in the other two directions, the frequency is increased on the original basis, and the triple mode is gradually transited into a dual-mode or single mode; if the sizes of the cavity and the dielectric resonant block in three axial directions are greatly different, and when the sizes of symmetric single sides in three directions of the X, Y and Z axes are different, frequencies of three modes of the triple modes are different; when the sizes of side lengths in three directions are greatly different, the base mode is a single mode; and when the sizes of the side lengths in three directions are not greatly different, the frequencies are not greatly different, and although the frequencies vary, a triple-mode state may also be maintained through the tuning device.
Coupling of triple modes is achieved through at least two nonparallel arranged coupling devices for changing orthogonal properties of the degenerate triple-mode electromagnetic field in the cavity in the concave triple-mode cavity resonant structure of the cavity, the coupling devices include cut corners and/or holes arranged beside the edges of the dielectric resonant block, or include chamfers and/or cut corners arranged beside the edges of the cavity, or include cut corners and/or holes arranged beside the edges of the dielectric resonant block, and chamfers/cur corners beside the edges of the cavity, or include tapping lines or/pieces arranged on nonparallel planes in the cavity, the cut corners take the shape of the triangular prism, the cuboid or the sector, the holes, take the shape of the circle, the rectangle or the polygon. After corners are cut or holes are formed, in case of frequency maintenance, side lengths of the dielectric resonant block are increased, and the Q value is slightly decreased. Depths of the cut corners or holes are of through or partial cut corners/partial hole structures according to required coupling amounts, and the coupling amounts are affected by the sizes of the cut corners/chamfers/holes. A coupling screw is arranged on a coupling tuning structure in a direction perpendicular or parallel to the cut corners and/or a direction parallel to the holes; the coupling screw is made of a metal, or the coupling screw is made of a metal and the metal is electroplated by copper or electroplated by silver, or the coupling screw is made of a dielectric, or the coupling screw is made of a surface metallized dielectric; the coupling screw takes a shape of any one of metallic rods, dielectric rods, metallic discs, dielectric discs, metallic, rods with metallic discs, metallic rods with dielectric discs, dielectric rods with metallic discs and dielectric rods with dielectric discs.
The resonant frequency of the triple mode in the direction of the X axis is achieved by installing the tuning, screw or the tuning disc at the place with concentrated field intensity on one or two faces of the cavity corresponding to the X axis so as to change the distance or change capacitance; the resonant frequency in the direction of the Y axis is achieved by additionally installing the tuning screw or the tuning disc at the place with concentrated field intensity on one or two faces of the Y axis corresponding to the cavity so as to change the distance or change capacitance; and the resonant frequency in the direction of the Z axis is achieved by additionally installing the tuning, screw or the tuning disc at the place with concentrated field intensity on one or two faces of the Z axis corresponding to the cavity so as to change the distance or change capacitance.
The triple-mode structure with Q value transition of the dielectric resonant is arbitrarily arranged and combined with the single-mode resonant structure, the dual-mode resonant structure and the triple-mode resonant structure in different modes to form required filters of different sizes; the filter has function properties of band pass, band stop, high pass, low pass and the duplexer, the multiplexer formed between them; and a coupling of any two resonant cavities formed by permutation and combination of the single-mode resonant structure and any one of the dual-mode resonant structure and the triple-mode resonant structure is achieved through the size of the window between the two resonant cavities necessarily when resonant rods in two resonant structures are parallel.
Some embodiments of the disclosure have the beneficial effects that the structure is simple in structure and convenient to use; by setting the ratio of the size of the single side of the inner wall of a metallic cavity of a dielectric triple mode to the size of the single side of the dielectric resonant block within 1.01-1.30, the dielectric resonant block is matched with the cavity to form the triple-mode structure while reverse turning of specific parameters is, achieved, and thus a high Q value is ensured when the dielectric resonant block and the cavity are at a small distance apart. Furthermore, some embodiments disclose a filter with the concave triple-mode cavity resonant structure, and compared with a triple-mode filter known to inventors, the filter has insertion loss reduced by 30% or greater on premise of same frequencies and same volumes. Dielectric resonant frequency transition triple-mode structures formed by the cube-like dielectric resonant block, the dielectric support frame and the cover plate of the cavity of the disclosure have magnetic fields orthogonal to and perpendicular to one another in directions of the X, Y and Z axes, thus three non-interfering resonant modes are formed, a higher-order mode frequency is transited into a high Q value base-mode frequency, coupling is formed among three magnetic fields, and different bandwidth demands of the filters, are met by adjusting coupling intensity. When two filters with the concave triple-mode cavity resonant structure are used, in a 1800 MHz frequency filter, a volume equivalent to six single cavities of an original cavity is achieved, the volume may be reduced by 40% on the basis of an original cavity filter, and the insertion loss may also be reduced by about 30%. Since the volume is greatly reduced, and the processing time and electroplating areas are correspondingly reduced, the cost is still equivalent to that of the cavity although the dielectric resonant block is used, if the material cost of the dielectric resonant block is greatly reduced, the design may have obvious cost advantages, when the filter has multiple cavities, three triple-mode structure may be used, and volume and performance may be obviously improved. Furthermore, on premise that the Q value of a single cavity is not greatly decreased, on the basis of the triple-mode resonant structure, a structure of the dielectric resonant block and/or cavity is changed (at least one concave end face is provided), so that the tuning range of the tuning screw is increased, meanwhile, the sensitivity to resonant frequencies is reduced due to the small distance between the cavity and the dielectric resonant block, thereby facilitating production debugging and reducing production cost.
In the figures: 1—cavity, 2—dielectric resonant block, 3—dielectric support frame, B1—first dielectric support frame, B2—second dielectric support frame, B3—third dielectric support frame, B4—fourth dielectric support frame, B5—fifth dielectric support frame, B6—sixth dielectric support frame.
An embodiment of the disclosure discloses a concave triple-mode cavity resonant structure which includes a cavity and a cover plate, wherein the cavity is internally provided with a dielectric resonant block and a dielectric support frame; the cavity takes a cube-like shape; the dielectric resonant block takes a cube-like shape and at least one end face is concave; the dielectric support frame is connected with the dielectric resonant block and an inner wall of the cavity, respectively; the dielectric resonant block and the dielectric support frame form a triple-mode dielectric, resonant rod; a dielectric constant of the dielectric support frame is smaller than a dielectric constant of the dielectric resonant block; when a ratio K of the size of a single side of the inner wall of the cavity to the size of a single side of the dielectric resonant block is: when K is greater than or equal to a transition point 1 and is smaller than or equal to a transition point 2, a Q value of a higher-order mode adjacent to a base mode is transited into ‘a’ value of the base mode of the triple-mode cavity resonant structure, a base-mode resonant frequency after transition is equal to a base-mode resonant frequency prior to transition, a Q value of the base mode after transition is greater than a Q value of the base mode prior to transition, and a Q value of the higher-order mode adjacent to the base mode after transition is smaller than a Q value of the higher-order mode adjacent to the base mode prior to transition; the triple-mode dielectric resonant structure is internally provided with a coupling structure for changing orthogonal properties of a degenerate triple-mode electromagnetic field in the cavity; and the triple-mode dielectric resonant structure is internally provided with a frequency tuning device for changing degenerate triple-mode resonant frequencies in the cavity.
In an exemplary embodiment of the disclosure the concave triple-mode cavity resonant structure includes a cavity and a cover plate, wherein the cavity is internally provided with a dielectric resonant block and a dielectric support frame; the cavity takes a cube-like shape and at least one end face is concave; the dielectric resonant block takes a cube-like shape; the dielectric support frame is connected with the dielectric resonant block and an inner wall of the cavity, respectively; the dielectric resonant block and the dielectric support frame form a triple-mode dielectric resonant rod; a dielectric constant of the dielectric support frame is smaller than a dielectric constant of the dielectric resonant block; when a ratio K of the size of a single side of the inner wall of the cavity to the size of a single side of the dielectric resonant block is: when K is greater than or equal to a transition point 1 and is smaller than or equal to a transition point 2, a Q value of a higher-order mode adjacent to a base mode is transited into a Q value of the base mode of the triple-mode cavity resonant structure, a base-mode resonant frequency after transition is equal to a base-mode resonant frequency prior to transition, a Q value of the base mode after transition is greater than a Q value of the base mode prior to transition, and a Q value of the higher-order mode adjacent to the base mode after transition is smaller than a Q value of the higher-order mode adjacent to the base mode prior to transition; the triple-mode dielectric resonant structure is internally provided with a coupling structure for changing orthogonal properties of a degenerate triple-mode electromagnetic field in the cavity; and the triple-mode dielectric resonant structure is internally provided with a frequency tuning device for changing degenerate triple-mode resonant frequencies in the cavity.
In an exemplary embodiment of the disclosure, the concave triple-mode cavity resonant structure includes a cavity and a cover plate, wherein the cavity is internally provided with a dielectric resonant block and a dielectric support frame; the cavity takes a cube-like shape and at least one end face is concave; the dielectric resonant block takes a cube-like shape and at least one end face is concave; the dielectric support frame is connected with the dielectric resonant block and an inner wall of the cavity, respectively; the dielectric resonant block and the dielectric support frame form a triple-mode dielectric resonant rod; a dielectric constant of the dielectric support frame is smaller than a dielectric constant of the dielectric resonant block; when a ratio K of the size of a single side of the inner wall of the cavity to the size of a single side of the dielectric resonant block is: when K is greater than or equal to a transition point 1 and is smaller than or equal to a transition point 2, a Q value of a higher-order mode adjacent to a base mode is transited into a Q value of the base mode of the triple-mode dielectric resonant structure, a base-mode resonant frequency after transition is equal to a base-mode resonant frequency prior to transition, a Q value of the base mode after transition is greater than a Q value of the base mode prior to transition, and a Q value of the higher-order mode adjacent to the base mode after transition is smaller than a Q value of the higher-order mode, adjacent to the base mode prior to transition; the triple-mode dielectric resonant structure is Internally provided with a coupling structure for changing orthogonal properties of a degenerate triple-mode electromagnetic field in the cavity; and the triple-mode dielectric resonant structure is internally provided with a frequency tuning device for changing degenerate triple-mode resonant frequencies in the cavity.
In an exemplary embodiment of the disclosure, the dielectric resonant block is of a solid structure or hollow structure, a hollow part of the dielectric resonant block of the hollow structure is filled with air or a nested dielectric resonant block, and a volume of the nested dielectric resonant block is smaller than or equal to a volume of a hollow chamber.
In an exemplary embodiment of the disclosure, the nested dielectric resonant block takes a cube-like shape and at least one end face is concave.
In an exemplary embodiment of the disclosure, a film dielectric is arranged ori at least one end face of the nested dielectric resonant block.
In an exemplary embodiment of the disclosure, a film dielectric is arranged on at least one end face of the cavity or/and at least one end face of the dielectric resonant block.
In an exemplary embodiment of the disclosure, a value of the transition point 1 and a K value of the transition point 2 both vary according to different base-mode resonant frequencies of the dielectric resonant block. dielectric constants of the dielectric resonant block, and dielectric constants of the support frame.
In an exemplary embodiment of the disclosure, when the base-mode resonant frequency of the dielectric resonant block after transition remains unchanged, the Q value of the triple-mode dielectric resonant structure is relevant to the K value, the dielectric constant of the dielectric resonant block and the size of the dielectric resonant block.
In an exemplary embodiment of the disclosure, when the K value is increased to the maximum from 1.0, the K value has three Q value transition points within a variation range, each Q value, transition point enables the Q value of the base mode of the K value and the Q value of the higher-order mode adjacent to the base mode of the K value to be transited; when the Q value of the base mode is lower than the Q value of the higher-order mode adjacent to the base mode, the Q value of the higher-order mode adjacent to the base mode is transited into the Q value of the base mode, and the Q value of the base mode is higher than that prior to transition; and when the Q value of the base mode is higher than the Q value of the higher-order mode adjacent to the base mode, the value of the higher-order mode adjacent to the base mode is transited into the Q value of the base mode, and the Q value of the base mode is lower than that prior to transition.
In an exemplary embodiment of the disclosure, in four areas formed by a start point and a final point of the K value and the three value Q transition points, the Q value of the base mode and the Q value of the higher-order mode adjacent to the base mode vary along with variation of cavity sizes and dielectric resonant block sizes, and different areas have different requirements when being applied to a filter.
In an exemplary embodiment of the disclosure, the value of the transition point 1 is greater than or equal to 1.03 and smaller than or equal to 1.30, the value of the transition point 2 is greater than or equal to 1.03 and smaller than or equal to 1.30, and the value of the transition point 1 is smaller than the value of the transition point 2.
In an exemplary embodiment of the disclosure, the coupling structure is arranged on the dielectric resonant block, and the coupling structure at least includes two nonparallel arranged holes and/or grooves and/or cut corners and/or chamfers.
In an exemplary embodiment of the disclosure, the grooves or the cut corners or the chamfers are arranged on edges of the dielectric resonant block.
In an exemplary embodiment of the disclosure, the holes or grooves are arranged on an end face of the dielectric resonant block, central lines of the holes or grooves are parallel to edges of end faces in which holes or grooves are formed perpendicularly to the dielectric resonant block.
In an exemplary embodiment of the disclosure, the coupling structure is arranged on the cavity, and the coupling structure at least includes two nonparallel arranged chamfers and/or bosses arranged at inner corners of the cavity and/or tapping lines/pieces arranged in the cavity and do not contact with the dielectric resonant block.
In an exemplary embodiment of the disclosure, a frequency tuning device includes a tuning screw arranged on the cavity and/or a film arranged on the surface of the dielectric resonant block and/or a film arranged on the inner wall of the cavity and/or a film arranged on the inner wall of the cover plate.
In an exemplary embodiment of the disclosure, at least one dielectric support frame is arranged on at least one end, face of the dielectric resonant block.
The disclosure also discloses a filter with the concave triple-mode cavity resonant structure. The filter includes a cavity, a cover plate and an input/output structure, and the cavity is at least internally provided with one concave triple-mode cavity resonant structure.
In an exemplary embodiment of the disclosure, the concave triple-mode cavity resonant structure is combined with a single-mode resonant structure, a dual-mode resonant structure and a triple-mode resonant structure in different modes to form filters of different volumes; a coupling of any two resonant cavities formed by permutation and combination of the concave triple-mode dielectric resonant structure and any one of the single-mode resonant structure; the dual-mode resonant structure and the triple-mode resonant structure is achieved through a size of a window between the two resonant cavities necessarily when resonant rods in the two resonant cavities are parallel, and the size of the window is determined according to a coupling amount; and the filter has function properties of band pass, band stop, high pass, low pass and a duplexer, a multiplexer and a combiner formed thereby.
In an exemplary embodiment of the disclosure, when a resonant frequency of the concave triple-mode cavity resonant structure is maintained, a triple-mode Q value is relevant to the ratio K of the side length of the inner wall of the cavity to the side length of the dielectric resonant block, the dielectric constant of the dielectric resonant block and, a size variation range of the dielectric resonant block, and the range of the K value is relevant to different resonant frequencies and dielectric constants of the dielectric resonant rod and the dielectric support frame.
In the above technical solution, the variation range of the ratio K of the side length of the inner wall of the cavity in the concave triple-mode cavity resonant structure to the size of the dielectric resonant block is that when the K value is increased to the maximum from 1.0, the K value has three Q value transition points within the variation range, each transition point enables the Q value of the base-mode resonant frequency to be transited into the Q value of an adjacent higher-order mode resonant frequency, and when an adjacent Q value of the higher-order mode is transited into the Q value of the base mode, the Q value of the base mode and the Q value of the higher-order mode are increased when being compared with that prior to transition (i.e. both the Q value of the base mode and the Q value of the higher-order mode increase with increasing the K value).
In an exemplary embodiment, in four areas formed by the start point and the final point of the K value and the three value Q transition points, the Q value of the base mode and the adjacent Q value of the higher-order mode gradually vary along with variation of cavity sizes and dielectric resonant rod sizes, and different areas have different requirements when being applied to the filter (application in different areas is explained in the description and examples).
In an exemplary embodiment, the dielectric resonant block of the disclosure is of a solid structure of a cube-like shape, the cube-like shape is defined as that the dielectric resonant block is a cuboid or cube, when the dielectric resonant block has a same size in X, Y and Z axes, a degenerate triple mode is formed, and the degenerate triple-mode is coupled with other single cavities to form a passband filter; when differences of sizes in three directions along the X, Y and Z axes are slightly unequal, orthogonal-like triple-mode resonant is formed, if an orthogonal-like triple-mode is capable of coupling with other cavities into the passband filter, the sizes are acceptable, and if the orthogonal-like triple-mode cannot be coupled with other cavities into the passband filter, the sizes are unacceptable; and when the differences of the sizes in the three directions along the X, Y and Z axes are greatly different, the degenerate triple-mode or orthogonal-like triple-mode cannot be formed, three modes of different frequencies are formed instead, thus the modes cannot be coupled with other cavities into the passband filter, and the sizes are unacceptable.
In an exemplary embodiment, the concave triple-mode cavity resonant structure is internally provided with at least two nonparallel arranged coupling devices for changing orthogonal properties of a degenerate triple-mode electromagnetic field in the cavity, each of the coupling devices includes cut corners and/or holes arranged beside edges of the dielectric resonant block, or includes chamfers and/or cut corners arranged beside the edges of the cavity, or includes cut corners and/or holes arranged beside the edges of the dielectric resonant block, and chamfers/cut corners arranged besides the edges of the cavity, or includes tapping lines or/pieces arranged on nonparallel planes in the cavity, the cut corners take a shape of a triangular prism, a cuboid or a sector, the holes take a shape of a circle, a rectangle or a polygon. After corner cutting or hole formation, in case of frequency holding, side lengths of the dielectric resonant block are increased, and the Q value is slightly decreased; depths of the cut corners or holes are of through or partial cut corners/partial hole structures according to required coupling amounts; the coupling amounts are affected by the sizes of the cut corners/chamfers/holes; a coupling tuning structure includes a coupling screw arranged in a direction perpendicular or parallel to the cut corners and/or a direction parallel to the holes; the coupling screw is made of a metal, or the coupling screw is made of a metal and the metal is electroplated by copper or electroplated by silver, or the coupling screw is made of a dielectric, or the coupling screw is, made of a surface metallized dielectric; the coupling screw takes a shape of any one of metallic rods, dielectric rods, metallic discs, dielectric discs, metallic rods with metallic discs, metallic rods with dielectric discs, dielectric discs with metallic discs and dielectric rods with dielectric discs.
In an exemplary embodiment, the concave triple-mode cavity resonant structure forms the degenerate triple-mode in directions, along the X, Y and Z axes, and a resonant frequency of the degenerate triple-mode in the direction of an X axis is achieved by additionally installing a tuning screw or a tuning disc at a place with concentrated field intensity on one or two faces of the X axis corresponding to the cavity so as to change a distance or change capacitance: a resonant frequency in the direction of a Y axis is achieved by additionally installing a tuning screw or a tuning disc at a place with concentrated field intensity on one or two faces of the Y axis corresponding to the cavity so as to change a distance or change capacitance; a resonant frequency in the direction of a Z axis is achieved by additionally installing a tuning screw or a tuning disc at a place with concentrated field intensity on one or two faces of the Z axis corresponding to the cavity so as to change a distance or change capacitance; dielectric constant films of different shapes and thicknesses are adhered to a surface of the dielectric resonant block, the inner wall of the cavity or cover plate and the bottom of the tuning screw, and the films are made of a ceramic dielectric or a ferroelectric material, and frequencies are adjusted by changing dielectric constants; the tuning screw or the tuning disc is made of a metal, or the tuning screw or the tuning disc is made of a metal and the metal is electroplated by copper or electroplated by silver, or the tuning disc or the tuning disc is made of a dielectric, or the tuning screw or the tuning disc is made of a surface metallized medium; the tuning screw takes a shape of any one of metallic rods, dielectric rods, metallic discs, dielectric discs, metallic rods with metallic discs, metallic rods with dielectric discs, dielectric discs with metallic discs and dielectric rods with dielectric discs; a frequency temperature coefficient of the dielectric resonant block that takes the cube-like shape is controlled by adjusting proportions of dielectric materials, and is compensated according to frequency deviation variation of the filter at different temperatures; and when the dielectric support frame is fixed with the inner wall of the cavity, in order to avoid stress caused by the cavity and the dielectric materials in a sudden temperature variation environment, an elastomer for transition is adopted therebetween, so that reliability risks caused by expansion coefficients of materials is buffered.
In an exemplary embodiment, the concave triple-mode dielectric resonant structure includes the cavity, the dielectric resonant block and the support frame; when the cavity takes the cube-like shape, a single cube-like dielectric resonant block is and the dielectric support frame are installed in any one axial direction of the cavity, and a center of the dielectric resonant block coincides with or approaches to a center of the cavity. An approximate air dielectric support frame supports with any one single face of a cube-like dielectric block, or supports with six faces, or supports with different combinations of two different faces; three faces, four faces and five faces, the dielectric support frame on each face is one or more dielectric support frames, and one or more support frames are installed on different faces, according to demands. A support frame of which the dielectric constant is, greater than a dielectric constant of air and smaller than a dielectric constant of the dielectric resonant block supports with any one single face of the cube-like dielectric block, or supports with six faces, or supports with different combinations of two different faces, three faces, four faces and five faces; a face without the support frame is air; the air face is arbitrarily combined with the dielectric support frame; the dielectric support frame on each face is one or more dielectric support frames, or is a complex dielectric constant support frame composed of multiple layers of different dielectric constant dielectric materials; single-layer and multi-layer dielectric material support frames are arbitrarily combined with cube-like dielectric blocks; one or more support frames are installed on different faces according to demands; on faces with the support frames, to hold the triple-mode frequencies and the Q value, the size corresponding to the axial direction of the dielectric resonant block of the dielectric support frame is slightly reduced; a single face support combination supports any one face of the dielectric resonant block, and particularly an under surface or bearing surface in a vertical direction; a support combination of two faces includes parallel faces such as upper and lower faces, front and rear faces and left and right faces, and also includes nonparallel faces such as upper and front faces, upper and rear faces, upper and left faces and upper and right faces; a support combination of three faces, includes three faces perpendicular to one another, or two parallel faces and one nonparallel face; a support combination of four faces includes two pairs of parallel faces or a pair of parallel faces, and two another nonparallel faces; a support combination of five faces includes support structures of other faces except any one face of a front face/a rear face/a left face/a right face/an upper face/a lower face; and a support combination of six faces includes support structures of all faces of a front face/a rear face/a left face/a right face/an upper face/a lower face.
In an exemplary embodiment, any end of the cube-like dielectric resonant block and the dielectric support frame are connected in a mode of crimping, adhesion or sintering; connection is one face connection or combined connection of different faces; multi-layer dielectric support, frames are fixed in modes of adhesion, sintering, crimping and the like; the dielectric support frame and the inner wall of the cavity are connected in a mode of adhesion, crimping, welding, sintering or screw fixation; a radio frequency channel formed by coupling of radio frequency signals in directions of the X, Y and Z axes of the triple mode causes loss and generates heat, the dielectric resonant block is sufficiently connected with the inner wall of the cavity through the dielectric support frame, and thus the heat is conducted into the cavity for heat dissipation.
In an exemplary embodiment, the cube-like dielectric resonant block has a single dielectric constant or composite dielectric constants; the dielectric resonant block with the composite dielectric constants is formed by at least two materials of different dielectric constants; the materials of different dielectric constants are combined up and down, left and right, asymmetrically or in a nested mode; when the materials of different dielectric constants are nested in the dielectric resonant block, one or more layers are nested; and the dielectric resonant block with the composite dielectric constants needs to comply with variation rules of the Q value transition points. When the dielectric resonant block is subjected to cut side coupling among triple modes, to hold the required frequency, corresponding side lengths of two faces adjacent to the cut sides are adjusted. The dielectric resonant block is, made, of a ceramic or dielectric material, and dielectric sheets of different thicknesses and different dielectric constants are added on the surface of the dielectric resonant block.
In an exemplary embodiment, the dielectric constant of the dielectric support frame is similar to the air dielectric constant, or the dielectric constant of the support frame is greater than the air dielectric constant or smaller than the dielectric constant of the dielectric resonant block; the surface area of the dielectric support frame is smaller than or equal to that of the dielectric resonant block; and the dielectric support frame takes a shape of a cylinder, a cube or a cuboid. The dielectric support frame is of a solid structure or hollow structure, the dielectric support frame of the hollow structure includes a single hole or multiple holes, the hole takes a shape of a circle, a square, a polygon and an arc; the dielectric, support frame is made of air, plastics, ceramics and dielectrics; the dielectric support frame is connected with the dielectric resonant block; when the dielectric constant of the dielectric support is similar to the air dielectric constant, the dielectric support has no effect on the three-mode resonant frequency. when the dielectric constant of the dielectric support frame is greater than the air dielectric constant and smaller than the dielectric constant of the dielectric resonant block, in order to hold original triple-mode frequencies, the size corresponding to the axial direction of the dielectric resonant block of the dielectric support frame is slightly reduced; a support frame with a dielectric constant similar to that of air and a support frame with a dielectric constant smaller than that of the dielectric resonant block are combined and installed in different directions and different corresponding faces of the dielectric resonant block; and when the two support frames of different dielectric constants are combined for use, an axial direction size greater than that of a dielectric resonant block corresponding to an air support frame is slightly reduced on an original basis.
In an exemplary embodiment, the cavity takes the cube-like shape; to achieve coupling of three modes, on premise that the size of the dielectric resonant block is not changed, cut sides for achieving coupling of the three modes are processed on any two adjacent faces, of the cavity; the sizes of the cut sides are relevant to required coupling amounts; coupling of two of the three modes is achieved through the cut sides of the cube-like; other coupling is achieved through cut corners of two adjacent sides of the cavity; walls are not broken when corners of the adjacent sides of the cavity are cut; and cut corner faces are completely sealed with the cavity. The cavity is made of a metal or a nonmetal material, the surface of the metal and the nonmetal material is electroplated by copper or silver, and when the cavity is made of the nonmetal material, the inner wall of the cavity needs to be electroplated by a conductive material such as copper or silver, such as plastics and composite materials electroplated by copper or silver.
In an exemplary embodiment, the concave, triple-mode dielectric resonant structure is combined with a single-mode resonant structure, a dual-mode resonant structure and a triple-mode resonant structure in different modes to form filters of different volumes; coupling of any two resonant cavities formed by permutation and combination of the concave triple-mode dielectric resonant structure, the single-mode resonant structure, the dual-mode resonant structure and the triple-mode resonant structure is achieved through a size of a window between the two resonant cavities necessarily when resonant rods in the two resonant cavities are parallel, and the size of the window is determined according to a coupling amount; and the filter has function properties of band pass, band stop high pass, low pass and a duplexer, a multiplexer and a combiner formed thereby.
The dielectric constant of the cube-like dielectric resonant block of some embodiments in the disclosure is greater than the dielectric constant of the support frame; when the ratio of the size of the single side of the inner wall of the cavity to the size of the single side of the dielectric resonant block is within 1.03-1.30, the Q value of the higher-order mode is transited into the Q value of the base mode, a triple-mode dielectric Q value of the base mode is increased and the Q value of the higher-order mode is decreased, and compared with single mode and triple-mode dielectric filters known to inventors with same volumes and frequencies, the Q value is increased by 30% or greater; the triple-mode cavity structure is combined with single cavities of different types, for example, the triple-mode cavity structure is combined with a cavity single mode, the triple-mode is combined, with the TM mode and the triple-mode is combined with the TE single mode, the greater the number of triple-modes in the filter is, the smaller the volume of the filter is, and the smaller the insertion loss is; the concave triple-mode cavity resonant structure generates triple-mode resonant in directions of the X. Y and Z axes, and triple-mode resonance is generated in the directions of the X, Y and Z axes.
When the ratio of the side length of the inner wall of the cavity to the size of a corresponding side length of the dielectric resonant block is within 1.0 to the transition point 1 transited from the Q value, and when the ratio of 1.0, the cavity has a pure medium Q value, when the size of the cavity is increased, the Q value is continuously increased on the basis of a pure medium, the Q value of the higher-order mode is greater than the Q value of the base mode, and when the ratio is increased to the transition point 1, an original Q value of the higher-order mode is approximated to a new Q value of the base, mode.
After entering, into the transition point 1, in case that the base-mode resonant frequency is maintained, the Q value of the base mode is greater than the Q value of the higher-order mode. Along with increase of the ratio, the sizes of the dielectric block and the cavity are both increased, the Q value of the base mode is also increased, and, the Q value of the higher-order mode is also increased; when the ratio is approximate to the transition point 2 of Q value transition, the Q value of the base mode is the highest, between the transition point 1 transited from the Q value of the base mode and the transition point 2 transited from the Q value of the base mode, the frequency of the higher-order mode is approximate to or far away from the frequency of the base mode along with variation of the ratio of the cavity to the dielectric resonant block between the transition point 1 and the transition point 2 at times.
After entering the transition point 2, the Q value of the base mode is smaller than the Q value of the higher-order mode; along with increase of the ratio, the size of the dielectric resonant block is reduced, the size of the cavity is increased, the Q value of the base mode is constantly increased, and when the ratio is, approximate to a transition point 3, the Q value of the base mode is approximate to the Q value at the transition point 2.
When the ratio enters the transition point 3, the Q value of the base mode is increased along with increase of the ratio, the Q value of the higher-order mode is decreased along with increase of the ratio, the size of the dielectric resonant block is decreased along with increase of the ratio, and the size of the cavity is constantly increased; when the size is approximate to a ¾ wavelength size of the cavity, the size of the dielectric resonant block is constantly decreased, the Q value of the base mode is also decreased, and, the frequency of the higher-order mode is approximate to or far away from the frequency of the base mode along with increase of the ratio at times. A particular ratio of the size of the transition points is relevant to dielectric constants and frequencies of the dielectric resonant block and single or composite dielectric constants of the dielectric resonant block.
The side length of the inner wall of the cavity and the side length of the dielectric resonant block may be or may be not equal in three directions of the X, Y and Z axes. The triple mode is formed when the sizes of the cavity and the cube-like dielectric resonant block are equal in the X, Y and Z axes; size differences in three directions of the X, Y and Z axes may also be slightly unequal; when the sizes of single sides of the cavity in one direction of the X, Y and Z axes and the corresponding dielectric resonant block is different from the sizes of single sides in other two directions of the X, Y and Z axes, or any one of the sizes of symmetric single sides of the cavity and the dielectric resonant block are also different from the sizes of single sides in the other two directions, the frequency of one of the triple modes varies and is different from frequencies of the other two modes of the triple modes, and the larger the size difference is, the larger the difference of the frequency of one mode from those of the other two modes is; when the size in one direction is greater than the sizes in the other two directions, the frequency is decreased on an original basis; when the size in one direction is smaller than those in the other two directions, the frequency is increased on the original basis, and the triple mode is gradually transited into a dual-mode or single mode; if the sizes of the cavity and the resonant block in three axial directions are greatly different, and when the sizes of symmetric single sides in three directions of the X, Y and Z axes are different, frequencies of three modes of the triple modes are different; when the sizes of side lengths in three directions are greatly different, the base mode is a single mode; and when the sizes of the side lengths in three directions are not greatly different, the frequencies are not greatly different, and although the frequencies vary, a triple-mode state may also be maintained through the tuning device.
Coupling of triple modes is achieved through at least two nonparallel arranged coupling devices for changing orthogonal properties of the degenerate triple-mode electromagnetic field in the cavity in the concave triple-mode cavity resonant structure of the cavity, the coupling devices include cut corners and/or holes arranged beside the edges of the dielectric resonant block, or include chamfers and/or cut corners arranged beside the edges of the cavity, or include cut corners and/or holes arranged beside the edges of the dielectric resonant block, and chamfers/cur corners beside the edges of the cavity, or include tapping lines or/pieces arranged on nonparallel planes in the cavity, the cut corners take the shape of the triangular prism, the cuboid or the sector, the holes take the shape of the circle, the rectangle or the polygon. After corners are cut or holes are formed, in case of frequency maintenance, side lengths of the dielectric resonant block are increased. and the Q value is slightly decreased. Depths of the cut corners or holes are of through or partial cut corners/partial hole structures according to required coupling amounts, and the coupling amounts are affected by the sizes of the cut corners/chamfers/holes. A coupling screw is arranged on a coupling tuning structure in a direction perpendicular or parallel to the cut corners and/or a direction parallel to the holes; the coupling screw is made of a metal, or the coupling screw is made of a metal and the metal is electroplated by copper or electroplated by silver, or the coupling screw is made of a dielectric, or the coupling screw is made of a surface metallized medium; the coupling screw takes a shape of any one of metallic rods, dielectric rods, metallic discs, dielectric discs, metallic rods with metallic discs, metallic rods with dielectric discs, dielectric rods with metallic discs and dielectric rods with dielectric discs.
The resonant frequency of the triple mode in the direction of the X axis is achieved by installing the tuning screw or the tuning disc at the place with concentrated field intensity on one or two faces of the cavity corresponding to the X axis so as to change the distance or change capacitance: the resonant frequency in the direction of the Y axis is achieved by additionally installing the tuning screw or the tuning disc at the place with concentrated field intensity on one or two faces of the Y axis corresponding to the cavity so as to change the distance or change capacitance; and the resonant frequency in the direction of the Z axis is achieved by additionally installing the tuning screw or the tuning disc at the place with concentrated field intensity on one or two faces of the Z axis corresponding to the cavity so as to change the distance or change capacitance.
The triple-mode structure with Q value transition of the dielectric resonant is arbitrarily arranged and combined with the single-mode resonant structure, the dual-mode resonant structure and the triple-mode resonant structure in different modes to form required filters of different sizes; the filter has function properties of band pass, band stop, high pass, low pass and the duplexer, the multiplexer formed between them; and a coupling of any two resonant cavities formed by permutation and combination of the single-mode resonant structure and any one of the dual-mode resonant structure and the triple-mode resonant structure is achieved through the size of the window between the two resonant cavities necessarily when resonant rods in two resonant structures are parallel.
Some embodiments of the disclosure have the beneficial effects that the structure is simple in structure and convenient to use; by setting the ratio of the size of the single side of the inner wall of a metallic cavity of a dielectric triple mode to the size of the single side of the dielectric resonant block within 1.01-1.30, the resonant rod is matched with the cavity to form the triple-mode structure while reverse turning of specific parameters is achieved, and thus a high Q value is ensured when the resonant rod and the cavity are at a small distance apart. Furthermore, some embodiments disclose a filter with the concave triple-mode cavity resonant structure, and compared with a triple-mode filter known to inventors, the filter has insertion loss reduced by 30% or greater on premise of same frequencies and same volumes. Dielectric resonant frequency transition triple-mode structures formed by the cube-like dielectric resonant block, the dielectric support frame and the cover plate of the cavity of the disclosure have magnetic fields orthogonal to and perpendicular to one another in directions of the X. Y and Z axes, thus three non-interfering resonant modes are formed, a higher-order mode frequency is transited into a high Q value base-mode frequency, coupling is formed among three magnetic fields, and different bandwidth demands of the filters are met by adjusting coupling intensity. When two filters with the concave triple-mode cavity resonant structure are used in a 1800 MHz frequency filter, a volume equivalent to six single cavities of an original cavity is achieved, the volume may be reduced by 40% on the basis of an original cavity filter, and the insertion loss may also be reduced by about 30%. Since the volume is greatly reduced, and the processing time and electroplating areas are correspondingly reduced, the cost is still equivalent to that of the cavity although the dielectric resonant block is used, if the material cost of the dielectric resonant block is greatly reduced, the design may have obvious cost advantages, when the filter has multiple cavities, three triple-mode structure may be used, and volume and performance may be obviously improved. Furthermore, on premise that the Q value of a single cavity is not greatly decreased, on the basis of the triple-mode resonant structure, a structure of the dielectric resonant block and/or cavity is changed (at least one concave end face is provided) so that the tuning range of the tuning screw is increased, meanwhile, the sensitivity to resonant frequencies is reduced due to the small distance between the cavity and the dielectric resonant block, thereby facilitating production debugging and reducing production cost.
The advantage of the high-Q three-mode dielectric resonant structure in the case of volume is obvious. Furthermore, in the case where the single cavity volume is small, the Q value of the high-Q multimode dielectric resonant structure of the cavity is significantly higher than the Q value of the other forms of single cavity. The filter volume of the high-Q three-mode dielectric resonant structure is reduced by more than 30%. Meanwhile, the loss of the filter is reduced by 30%, and when the performance of the high-Q three-mode dielectric resonant structure filter is the same as that of the conventional filter, the volume of the high-Q three-mode dielectric resonant structure filter is significantly reduced by more than 50% relative to a conventional cavity filter.
A concave multi-mode cavity resonant structure described in fallowing embodiments includes:
a cavity taking a cube-like shape, a dielectric resonant block taking a cube-like shape with a concave end face, and a dielectric, support frame;
a cavity which is concave, a dielectric resonant block taking a cube-like shape, and a dielectric support frame;
a cavity and a dielectric resonant block which are both concave, and a dielectric support frame; and
the dielectric support frame is, manufactured in match with a structure, and the number may be one or more. Shapes may be regular shapes such as solid/hollow cylinders, solid/hollow square columns, or may also be irregular shapes, or are composed of multiple columns.
In order to ensure multiple modes and corresponding frequencies, the structure is not infinitely concave or does not infinitely protrude outwards but is subjected to limitation conditions. An example is taken for explanation, and others can be similarly obtained.
Eg: single cavity 26 mm*26 mm*26 mm, the dielectric support frame is Er9.8, Q*f is 100,000, an outer diameter is 5 mm, an inner diameter is 9.7 mm, the dielectric resonant block is Er43, and Q*f is 43,000.
Apparently, according to table 2, the longest side length 25.97 of the dielectric resonant block is already approximate to a side length 26 mm of the cavity, therefore, the concave size is 1.5 mm at most.
To understand the disclosure clearly, the disclosure is specifically described with specific embodiments and figures, and the description does not constitute any limitation to the disclosure.
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The above embodiments are only some embodiments of the disclosure and do not constitute any limitation to the disclosure, particularly shapes and numbers of the dielectric support frames.
For example, in embodiments 1-4, directions of three edges perpendicular to one another in the dielectric resonant block 2 are respectively defined as an X direction, a Y direction and a Z direction, the three directions are relative position directions and are not solely determined. The dielectric resonant block 2 forms an X-axis dielectric resonant block, a Y-axis, dielectric resonant block, and a Z-axis dielectric resonant block, with corresponding dielectric support frames in the three X, Y and Z directions. The X-axis dielectric resonant block, the Y-axis dielectric resonant block and the Z-axis dielectric resonant block are matched with an interior of the cavity to form three degenerate modes. A resonant frequency in the direction of the X axis can be achieved by additionally installing a tuning screw on a side wall corresponding to a metallic cavity to change a distance or change capacitance. A resonant frequency in the direction of the Y axis can be achieved by additionally installing a tuning screw on a side wall corresponding to a metallic cavity to change a distance or change capacitance. A resonant frequency in the direction of the Z axis can be achieved by additionally installing a tuning screw on a side wall corresponding to a metallic cavity to change a distance or change capacitance.
A radio frequency signal has loss after triple-mode resonant. Heat is generated when three degenerate modes in X, Y and Z directions in working, heat conduction can be achieved by enabling the dielectric resonant block and multiple dielectric support frames to sufficiently contact with walls of the metallic cavity, and thus a filter can work stably for a long time.
Coupling devices are arranged between every two of the three degenerate modes, particularly: the dielectric resonant block 2 is provided with a first plane j1 for coupling resonant modes in the X direction and the Y direction, a second plane j2 for coupling resonant modes in the Y direction and the Z direction, and a third plane j3 for coupling resonant modes in the X direction and the Z direction. Every two of the first plane j1 the second plane j2 and the third plane j3 are respectively perpendicular to each other. The first plane j1 is, parallel to an edge arranged along the Z direction, the second plane j2 is parallel to an edge arranged along the X direction, and the third plane is parallel to an edge arranged along the Y direction. That is, in the three degenerate modes, coupling of a degenerate mode in the X direction with a degenerate mode in the Y direction is achieved by the first plane j1 which is formed by cutting off a part of a corner along the direction of the Z axis, and the corner is formed by cross X and Y planes of a dielectric resonant block A. Coupling of a degenerate mode in the X direction with a degenerate mode in the Z direction is achieved by the second plane j2 which is formed by cutting off a part of a corner along the direction of the Z axis and the corner is formed by cross Y and Z planes of a dielectric resonant block. Coupling of a degenerate mode in the Y direction with a degenerate mode in the Z direction is achieved by the third plane j3 which is formed by cutting off a part of a corner along the direction of the Z axis and the corner is formed by cross Z and X planes of a dielectric resonant block. The larger the area of a coupling surface is, the larger the coupling amount is, and the smaller the coupling amount is otherwise. Transmission zero points may be formed by cross coupling of three degenerate modes formed by the dielectric resonant block. If coupling of an X direction resonant mode and a Y direction resonant mode and coupling of a Y direction resonant mode and a Z direction resonant mode are main coupling, coupling of the X direction resonant mode and the Z direction resonant mode is cross coupling.
In the above solution, according to actual coupling amounts, one or more first planes j1 are arranged. When more first planes j1 are arranged, the more first planes j1 are arranged in parallel. One or more second planes j2 are arranged. When more second planes j2 are arranged, the more second planes j2 are arranged in parallel. One or more third planes j3 are arranged. When more third planes j3 are arranged, the more third planes j3 are arranged in parallel.
In the above solution, the dielectric resonant block 2 is directly formed by a cube-like shape with approximate side lengths or by a cube dielectric with equal side lengths, the cube dielectric is formed by protruding outwardly at least one end face, or by overall or partially growing films on a surface, or is composed of cube-like shapes with approximate side lengths or cube dielectrics with equal side lengths, the cube dielectrics is formed by concaving at least one end face and overall or partially growing film dielectrics. The dielectric resonant block is made of a ceramic or dielectric.
In some embodiments, the dielectric resonant block 2 is directly formed by a cube-like shape with approximate side lengths or by directly concaving at least one end face of a cube dielectric with equal side lengths, or is composed of cube-like shapes with approximate side lengths or cube dielectrics with equal side lengths, the cube dielectrics is formed by concaving at least one end face and overall or partially growing film dielectrics. The dielectric resonant block 2 is made of a ceramic or dielectric.
In the above solution, one or more dielectric support frames 3 are designed. When more dielectric support frames 4 are arranged, the more dielectric support frames 3 are respectively installed between different faces of the dielectric resonant block 2 and inner walls of the cavity.
Shapes of more dielectric support frames 3 include, but not limited to, circles, ellipses, squares and irregular shapes that inner walls of the cavity are tightly matched with corresponding dielectric end faces. Materials of the dielectric support frame 3 include, but not limited to, plastics, dielectrics and air, and the dielectric support frame is of a solid structure or a structure with a hollow center. The dielectric resonant block 2 and the dielectric support frame 3 are connected in modes of, but not limited to, gluing and crimping. The dielectric resonant block and the dielectric support frame are connected in modes of, but not limited to, gluing, crimping, screw fastening and welding. The cavity takes a cube-like shape or a cube shape. The cavity is made of a metallic material, or the cavity is made of a metallic material and is an inner wall of the metallic material is coated by silver or copper, or the cavity is made of a nonmetallic material of which the surface is coated by a metallic layer. In order to reduce variation of frequencies at different ambient temperatures, material proportions of the dielectric resonant block may be adjusted according to different temperature divination to control frequency deviation, in addition, in order to ensure structure reliability, the dielectric support frame is made of an elastic material such as a plastic, so that the dielectric support frame of the structure is capable of counteracting influence of thermal expansion and cold contraction in different environments.
The dielectric support frame of the solid structure takes a shape of a solid structure, or is of a through tubular structure in the middle, or is a combination of multiple independent solid columns.
The dielectric support frame of the solid structure is made of plastics, ceramics or dielectrics, and a dielectric support frame of a non-solid structure is made of air.
Two end faces of the dielectric resonant block along the X direction are connected with the first dielectric support frame and the second dielectric support frame in a mode of gluing or crimping. Two end faces of the dielectric resonant block along the Y direction are connected with the third dielectric support frame and the fourth dielectric support, frame in a mode of gluing or crimping. Two end faces of the dielectric resonant block along the Z direction are connected with the fifth dielectric support frame and the sixth dielectric support frame in a mode of gluing or crimping.
In an embodiment, a total resonant block formed by resonant blocks in three X, Y and Z directions and the cavity form a triple-mode resonant cavity structure. The cavity takes the cube shape or cube-like shape. The cavity is made of the metallic material, or the cavity is made of the metallic material and the inner wall of the metallic material is coated by silver or copper, or the cavity is made of the nonmetallic material of which the surface is coated by the metallic layer.
In an embodiment, the total resonant block formed by resonant blocks in three X, Y and Z directions is connected with the inner wall of the cavity in a mode of gluing, crimping, screw fastening or welding. The total resonant block formed by resonant blocks in three X, Y and Z directions has compensation of frequencies along with temperature variation. The structure of the dielectric support frame of the total resonant block formed by resonant blocks in three X, Y and Z directions counteracts influence caused by thermal expansion and cold contraction in different environments by using a material of certain elasticity or a shape of an elastic structure, and the elastic material of the dielectric support frame is a plastic, a dielectric, a composite material, aluminum oxide and the like.
In the above solution, the resonant frequency of the degenerate triple mode in the direction of the X axis is achieved by additionally installing the tuning screw or the tuning disc at the place with concentrated field intensity on one or two faces of the X axis corresponding to the cavity so as to change the distance or change capacitance; the resonant frequency in the direction of the Y axis is achieved by additionally installing the tuning screw or the tuning disc at the place with concentrated field intensity on one or two faces of the Y axis corresponding to the cavity so as to change the distance or change capacitance; and the resonant frequency in the direction of the Z axis is achieved by additionally installing the tuning screw or the tuning disc at the place with concentrated field intensity on one or two faces, of the Z axis corresponding to the cavity so as to change the distance or change capacitance.
The tuning screw or the tuning disc is made of a metal, or the tuning screw or the tuning disc is made of a metal and the metal is electroplated by copper or electroplated by silver, or the tuning disc or the tuning disc is made of a dielectric, or the tuning screw or the tuning disc is made of a surface metallized dielectric.
The tuning screw takes the shape of any one of metallic rods, dielectric rods, metallic discs, dielectric discs, metallic rods with metallic discs, metallic rods with dielectric discs, dielectric rods with metallic discs and dielectric rods with dielectric discs.
In the above solution, at least two nonparallel arranged coupling structures for breaking orthogonality of degenerate multi-mode electromagnetic fields in the cavity are disposed on the dielectric resonant block and/or non-corresponding parts of the cavity. The coupling structures include cut corners and holes, arranged beside the edges of the dielectric resonant block and/or cut corners beside the edges of the cavity. The cut corners take the shape of a triangular prism or cube-like shape or sector. In the three degenerate modes, coupling of a degenerate mode in the X direction with a degenerate mode in the Y direction is achieved by a first plane which is formed by cutting off a part of a corner along the direction of the Z axis and the corner is formed by cross X and Y planes of the dielectric resonant block. Coupling screws are disposed on edges formed by cross X and Y planes of the cavity in a parallel or perpendicular manner to achieve fine tuning of coupling amounts. Coupling of the degenerate mode in the Y direction with a degenerate mode in the Z direction is achieved by a second plane which is formed by cutting off a part of a corner along the direction of the X axis, and the corner is formed by cross Y and Z planes of the dielectric resonant block. Coupling screws are disposed on edges formed by cross Y and Z planes of the cavity in a parallel or perpendicular manner to achieve fine tuning of coupling amounts. Coupling of the degenerate mode in the Z direction with the degenerate mode in the X direction is achieved by a third plane which is formed by cutting off a part of a corner along the direction of the Y axis, and the corner is formed by cross Z and X planes of a dielectric resonant block. Coupling screws are disposed on edges formed by cross Z and X planes of the cavity in a parallel or perpendicular manner to achieve fine tuning of coupling amounts.
In an embodiment, the coupling screw is made of a metal, or the coupling screw is made of a metal and the metal is electroplated, by copper or electroplated by silver, or the coupling screw is made of a dielectric, or the coupling screw is made of a surface metallized dielectric.
In an embodiment, the coupled screw takes a shape of any one of metallic rods, dielectric rods, metallic discs, dielectric discs, metallic rods with metallic discs, metallic rods with dielectric discs, dielectric rods with metallic discs and dielectric rods with dielectric discs.
In an embodiment, a radio frequency channel is formed by coupling of a resonant mode in the X direction and a resonant mode in the Y direction and coupling of a resonant mode in the Y direction and a resonant mode in the Z direction to cause loss and generate heat, the six dielectric support frames are sufficiently connected with the inner wall of the cavity to achieve heat conduction, and thus the heat is dissipated.
In an embodiment, multi-mode resonant structures with small distances, single-mode resonant cavities and triple-mode resonant cavities of different modes are combined in different modes to form filters of different volumes.
The filter has function properties of band pass, band stop, high pass, low pass and a combiner formed thereby.
Coupling of any two resonant cavities formed by permutation and combination of a triple-mode dielectric resonant cavity and any one of a single-mode resonant cavity, a dual-mode resonant cavity and a triple-mode resonant cavity is achieved through a size of a window between the two resonant cavities necessarily when dielectric resonant blocks in the two resonant cavities are parallel.
It should be understood that the above is only embodiments of the disclosure, but the scope of protection of the disclosure is not limited to this. Changes or replacements easily made by any of those skilled in the art within the scope of the technology disclosed by the disclosure shall be covered by the scope of protection of the disclosure. The contents not described in detail in the description belong to the conventional art known to those skilled in the art.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201811155049.9 | Sep 2018 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2018/125166 | 12/29/2018 | WO |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2020/062686 | 4/2/2020 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 11239540 | Meng | Feb 2022 | B2 |
| 20040178864 | Andoh | Sep 2004 | A1 |
| 20170263996 | Karhu | Sep 2017 | A1 |
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| Bakr Mustafa S et al.: “Miniature Triple-Mode Dielectric Resonator Filters”, 2018 IEEE/MTT-S Internation Microwave Symposium-IMS, IEEE, Jun. 10, 2018, pp. 1249-1252, XP033387893. |
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| Number | Date | Country | |
|---|---|---|---|
| 20210328320 A1 | Oct 2021 | US |
