The present invention relates to a resonator, a filter, a nonreciprocal circuit device, and a communication apparatus for use in, for example, wireless communication in the microwave band or millimeter-wave band or transmission and reception of electromagnetic waves.
Non-Patent Document 1 and Patent Documents 1 and 2 disclose magnetic-resonance isolators. Such magnetic-resonance isolators of the related art utilize a phenomenon in which when high-frequency currents of equal amplitude whose phases differ by π/2 radians flow in two perpendicular lines, a rotating magnetic field (circularly polarized wave) is produced at the intersection thereof and the rotational direction of the circularly polarized wave reverses depending on the traveling direction of the electromagnetic wave along the two lines. Specifically, a ferrimagnetic member is disposed at the intersection, and a static magnetic field needed for magnetic resonance is applied. When the traveling direction of the electromagnetic wave propagating in the principal line is the reverse direction, the circularly polarized wave produced at the intersection is a positive circularly polarized wave, and resonance absorption occurs. When the direction of the electromagnetic wave propagating in the principal line is the forward direction, the circularly polarized wave is a negative circularly polarized wave, and resonance absorption does not occur so that the electromagnetic wave can be transmitted.
Neither of Patent Document 1 or 2 or Non-Patent Document 1 discloses a substantially cross-shaped strip-line resonance isolator that is formed by intersecting microstrip lines. The facts that the fundamental mode is a dual mode and that the magnetic field vectors are orthogonal to each other in the vicinity of the intersection, i.e., that a circularly polarized wave is produced at a certain frequency, are utilized to form a magnetic-resonance isolator. However, such a nonreciprocal circuit device of the related art is designed to operate at a half wavelength or a quarter wavelength because of the use of microstrip lines. It is difficult to reduce the size because the pattern size is determined based on the dielectric constant of the substrate. Further, the magnetic field distribution is of the distributed-constant type, and a region in which a circularly polarized wave having the magnetic resonance absorption effect is produced is also of the distributed-constant type. Thus, the absorption efficiency with respect to the volume of a magnetic-material member is low, and it is also difficult to reduce the size of the magnetic-material member.
In a microstrip-line resonator composed of a nonreciprocal circuit device of the related art, the magnetic field vectors are expanded to the outside in which no microstrip-line electrodes exist. This limits the compactness and integration of the circuit.
It is an object of the present invention to provide a resonator, a filter, and a nonreciprocal circuit device that can be compact and integrated without increasing the complexity of the overall structure, and a communication apparatus including the same.
A resonator of the present invention includes a substrate, and a conductor layer defined on the substrate, wherein the conductor layer is provided with first and second conductor openings communicating with each other via a first slit, and third and fourth conductor openings communicating with each other via a second slit, and the first slit and the second slit intersect each other.
The resonator of the present invention further includes a capacitance-forming conductor layer that is brought into proximity to the conductor layer with an insulating layer therebetween in a thickness direction of the insulating layer, wherein the capacitance-forming conductor layer is placed at a position facing four sections of the conductor layer that is sectioned by the intersecting first and second slits.
In the resonator of the present invention, a magnetic field or an electric field of two resonant modes in which a magnetic field vector enters or exits the first through fourth conductor openings is unbalanced to resolve the degeneracy of the two resonant modes.
In the resonator of the present invention, at least one of the first through fourth conductor openings includes a resonant element including the following structure.
The resonant element includes one or a plurality of ring-shaped resonance units, each resonance unit being defined by one or a plurality of conductor lines and having a capacitive area and an inductive area, wherein an end of the conductor line is brought into adjacency with the other end of the conductor line or an end of another conductor line included in the same resonance unit in a width direction or a thickness direction to form the capacitive area.
A filter of the present invention includes the resonator, and signal input/output means coupled to the resonator.
A nonreciprocal circuit device of the present invention includes the resonator, and a magnet that applies a direct-current magnetic field to a ferrite member, the ferrite member being defined in a region surrounded by the first through fourth conductor openings.
In the nonreciprocal circuit device of the present invention, the first slit and the second slit intersect at substantially a right angle.
A communication apparatus of the present invention includes at least one of the resonator, the filter, and the nonreciprocal circuit device.
According to the resonator of the present invention, the conductor layer on the substrate is provided with the first and second conductor openings communicating with each other via the first slit, and the third and fourth conductor openings communicating with each other via the second slit, and the first slit and the second slit intersect each other. Therefore, the intersecting first and second slits act as capacitive areas due to the gaps, and the first through fourth conductor openings act as inductive areas. The capacitive areas and the inductive areas are used to operate as a slot resonator. The magnetic field vector in this resonant mode enters and exits four slots, and is not expanded outwards in the plan-view direction from the conductor openings, resulting in less leakage of energy to the outside of the resonator. This is effective in enhancing the compactness and integration of the circuit.
Further, according to the present invention, the capacitance-forming conductor layer is opposed to the conductor layer with the insulating layer therebetween, and the capacitance-forming conductor layer is placed at a position facing four sections of the conductor layer sectioned by the intersecting first and second slits. With the structure of the conductor layer, the dielectric layer, and the conductor layer, a capacitance is generated in the thickness direction, and a large capacitance in proportion to the dimension of the capacitance-forming conductor layer is obtained. This allows a reduction in the size of the resonator.
Further, according to the present invention, the magnetic field or electric field of two resonant modes in which the magnetic field vector enters or exits the first through fourth conductor openings is unbalanced to resolve the degeneracy of the two resonant modes, resulting in a coupled two-stage resonator. It is possible to provide a filter band design including the resonator and input/output means.
Further, according to the present invention, at least one of the first through fourth conductor openings includes a step-ring resonant element. The presence of the step-ring resonant element allows a reduction in current concentration due to the edge effect that occurs at the edges of the conductor opening, and the loss reduction effect is achieved.
Further, according to the present invention, the filter includes the resonator having any of the above-described structures and signal input/output means coupled to the resonator, thus achieving a compact, integrated design.
Further, according to the present invention, a ferrite member is placed in a region surrounded by the first though fourth conductor openings of the resonator having any of the above-described structures, and a magnet that applies a direct-current magnetic field to the ferrite member is provided. Thus, a nonreciprocal circuit device, such as an isolator, is provided.
Further, according to the present invention, the first slit and the second slit intersect at substantially a right angle. This leads to a magnetic field distribution without deviation through the four conductor openings, and a high Q-factor is achieved equivalently in the even mode and the odd mode.
Further, according to the present invention, a compact, lightweight, low-cost communication apparatus including at least one of the resonator, filter, and nonreciprocal circuit device, which are compact and integrated without increasing the complexity of the overall structure, is obtained.
FIGS. 1(A) and 1(B) are diagrams showing a structure of a resonator according to a first embodiment.
FIGS. 2(A) and 2(B) are diagrams showing two resonant modes of the resonator.
FIGS. 3(A)-3(D) are diagrams showing other two resonant modes in the resonator.
FIGS. 4(A) and 4(B) are diagrams showing a structure of a resonator according to a second embodiment.
FIGS. 5(A) and 5(B) are diagrams showing two resonant modes of the resonator.
FIGS. 6(A)-6(C) are diagrams showing a structure of a resonator according to a third embodiment.
FIGS. 7(A) and 7(B) are diagrams showing the shape of a capacitance-forming conductor layer of the resonator.
FIGS. 8(A)-8(C) are diagrams showing a structure of a resonator according to a fourth embodiment.
FIGS. 9(A)-9(E) are diagrams showing a structure of a resonator according to a fifth embodiment.
FIGS. 10(A)-10(E) are diagrams showing a structure of a resonator according to a sixth embodiment.
FIGS. 11(A)-11(C) are diagrams showing the operation of a resonant element used in the resonator.
FIGS. 12(A) and 12(B) are equivalent circuit diagrams of the resonant element used in the resonator.
FIGS. 13(A)-13(F) are diagrams showing a structure of a resonator according to a seventh embodiment.
FIGS. 14(A)-14(F) are diagrams showing a structure of a resonator according to an eighth embodiment.
FIGS. 15(A)-15(F) are diagrams showing a structure of a resonator according to a ninth embodiment.
FIGS. 16(A)-16(C) are diagrams showing a structure of a resonator according to a tenth embodiment.
FIGS. 17(A)-17(C) are diagrams showing a structure of a resonator according to an eleventh embodiment.
FIGS. 18(A)-18(C) are diagrams showing a structure of a resonator according to a twelfth embodiment.
FIGS. 19(A)-19(C) are diagrams showing a structure of a resonator according to a thirteenth embodiment.
FIGS. 20(A)-20(C) are diagrams showing a structure of a resonator according to a fourteenth embodiment.
FIGS. 21(A)-21(C) are diagrams showing a crossing angle of magnetic field vectors.
FIGS. 22(A)-22(C) are diagrams showing a crossing angle of magnetic field vectors.
FIGS. 24(A)-24(D) are diagrams showing magnetic field distributions of the odd mode and the even mode of the resonator according to the third embodiment.
FIGS. 25(A)-25(D) are diagrams showing electric field distributions of the odd mode and the even mode of the resonator according to the third embodiment.
FIGS. 26(A) and 26(B) are diagrams showing a relationship between the resonator and a microstrip-line resonator of the related art.
1 dielectric substrate
2 conductor line
2′ conductor line aggregate
3 insulating layer
4 conductor layer
5 capacitance-forming conductor layer
6 conductor layer
7 shield electrode
8 input/output terminal
9 input/output-coupling electrode
10 via-hole
11 capacitance-coupling electrode
13 shield case
14 shield cap
15 substrate
16 ferrite core
17 magnet
100 resonant element
120 communication apparatus
AP conductor opening
SL slit
SLL slot
A resonator according to a first embodiment will be described with reference to FIGS. 1 to 3.
A shield cap 14 that covers an area in which the conductor openings AP1 to AP4 and the slits SL1 and SL2 are defined and that is DC-connected to the conductor layer 4 is attached to the top of the dielectric substrate 1.
FIGS. 2(A)-2(B) illustrate magnetic field distributions of two resonant modes generated by the four conductor openings AP1 to AP4 of the resonator. In FIGS. 2(A)-2(B), a broken-line arrow represents a magnetic field vector.
The four conductor openings AP1 to AP4 serve as individual inductive areas, and the slits SL1 and SL2 shaped into a cross serve as capacitive areas. When the conductor openings AP1 to AP4 and the slits SL1 and SL2 have a symmetrical shape with respect to the x and y axes, the distributions of the magnetic field vectors in the even mode and the odd mode have an overlapping relation when they are geometrically rotated by 90 degrees (90-degree rotation symmetry). In this case, the two modes are degenerate (in the state where two independent resonant modes have the same resonant frequency and are uncoupled).
FIGS. 3(A)-3(D) illustrate two other resonant modes using a combination of conductor openings and slits.
FIGS. 3(A)-3(D), a broken-line arrow represents a magnetic field vector, and dot and cross symbols represent directions of magnetic field vectors. The even and odd modes shown in FIGS. 2(A)-2(B) can be expressed in a manner in which the X and Y modes shown in FIGS. 3(A)-3(D) are coupled. In a strip-line resonator as disclosed in Non-Patent Document 1 or Patent Document 1 or 2, the magnetic field is distributed around an electrode. In this embodiment, however, most of the magnetic field vectors are distributed in the conductor openings AP1 to AP4, and are not expanded outwards in the plan-view direction from the conductor openings. This results in less leakage of energy to the outside of the resonator, which is effective in enhancing the compactness and integration of the circuit.
The resonator composed of the four conductor openings AP1 to AP4 and the two slits SL1 and SL2 defined on the conductor film 4 is shielded by the shield electrode 7 on the side of the dielectric substrate 1 and the shield cap 14. It is therefore possible to prevent the interference between the resonator and other components or circuits near the resonator.
Next, a resonator according to a second embodiment will be described with reference to FIGS. 4(A) through 5(B).
In
As shown in FIGS. 5(A)-5(B), the even mode and the odd mode can be expressed as two overlapping resonant modes, i.e., the resonant mode (X mode) using the conductor openings AP1 and AP2 and the slit SL1 and the resonant mode (Y mode) using the conductor openings AP3 and AP4 and the slit SL2. In this case, the resonant frequencies of the X and Y modes are equal. With respect to the even mode and the odd mode, the path length of the magnetic field vectors rotated around a pair of two conductor openings is longer in the odd mode than in the even mode. Therefore, the frequency of the odd mode is higher than the frequency of the even mode. That is, in the perturbation theory, work is performed on a magnetic field distribution when the distance between the openings increases, thus accounting for the higher frequency. Further, as the distance between the openings increases, the distribution of magnetic field density is flattened and the amount of induction is reduced, thus accounting for the higher frequency.
By resolving the degeneracy, therefore, a two-stage resonator in which two resonators are coupled is provided. As discussed below, the resonator is provided with input/output means, thus forming a filter having a two-stage resonator.
Next, a structure of a resonator according to a third embodiment will be described with reference to FIGS. 6(A) through 7(B) and 24(A) to 26(B).
The capacitance-forming conductor layer 5 allows an increase in the capacitance of the capacitive area, and, accordingly, allows a reduction in the size of the resonator for obtaining the desired resonant frequency.
Table 1 shows the directions of the electric field vectors at certain time. In Table 1, the + (plus) symbol represents upward, the − (minus) symbol represents downward, and the numeral 0 represents 0 as the average. As shown in
FIGS. 24(A)-24(D) and 25(A)-25(D) illustrate a magnetic field distribution and an electric field distribution of the resonator including the capacitance-forming conductor layer 5 shown in
Likewise, FIGS. 24(C), 24(D), 25(C), and 25(D) show the even mode. As is apparent from FIGS. 25(A)-25(D), in this example, the electric field of the even mode is affected by the cutout portions c of the capacitance-forming conductor layer 5, and the frequency increases to 3.40 GHz. The electric field of the odd mode, on the other hand, is not affected by the cutout portions c of the capacitance-forming conductor layer 5, and the frequency is maintained at 3.04 GHz.
Therefore, if the four conductor openings AP1 to AP4 and the two slits SL1 and SL2 are 90°-rotation-symmetric (vertically and horizontally symmetric), the degeneracy can be resolved to couple the X mode and the Y mode.
FIGS. 26(A)-26(C) are diagrams comparing the resonator according to the third embodiment with a strip-line resonator of the related art.
Further, as discussed below, due to the characteristics of the electromagnetic field distribution of the resonant modes, the proportion of an area in which a circularly polarized wave is generated is large.
FIGS. 8(A)-8(C) illustrate a structure of a resonator according to a fourth embodiment.
FIGS. 9(A)-9(E) illustrate a structure of a resonator according to a fifth embodiment.
By alternately laminating the conductor layers having the conductor openings AP1 to AP4 and the slits SL1 and SL2 and the capacitance-forming conductor layers 5, a large capacitance can be formed in the limited space (volume). Therefore, a lower frequency and a reduction in size are achieved.
FIGS. 10(A)-10(E) illustrate a structure of a resonator according to a sixth embodiment.
Similar to the resonator shown in FIGS. 9(A)-9(E), conductor layers 4 are disposed in the odd-numbered layers of a dielectric substrate 1, and capacitance-forming conductor layers 5 are disposed in the even-numbered layers. In the example shown in FIGS. 10(A)-10(E), the resonant element 100 is mounted on the top of each of four conductor openings AP1 to AP4.
As shown in
One resonance unit among the conductor lines 2a, 2b, 2c, 2d, and 2e will now be described with reference to FIGS. 11(A)-11(C).
The conductor line 2 wraps around itself one or more times with intervals of a constant width on the dielectric substrate 1, and both ends of the conductor line 2 are adjacent to each other in the width direction of the conductor line.
In
With regard to the distribution of current, as shown in
The resonance unit is composed of an inductive area with high impedance, and a capacitive area with low impedance, and the impedance changes stepwise. The resonance unit is therefore referred to as a step ring. A resonant element is composed of a plurality of resonance units, and is referred to as a multi-step-ring resonant element.
As such, an aggregate of the conductor lines 2 having a large number of lines is arranged in the limited space to form conductor lines having a large number of lines, and a compact resonator is formed. By rendering the line width of the fine electrode of the step ring resonant element smaller than the skin depth at the operating frequency, the loss reduction effect due to reduced skin effect can be achieved.
FIGS. 12(A)-12(B) are equivalent circuit diagrams of the resonant element 100 shown in FIGS. 10(A)-10(E). FIG. 12(B) shows an equivalent circuit of a slot resonator including a conductor film 4 having conductor openings AP1 to AP4 and slits SL1 and SL2 without forming the conductor lines 2a, 2b, and 2c shown in
The resonance units formed of the conductor lines 2a to 2e shown in
Thus, a multi-step-ring resonant element is placed inside a conductor opening serving as an inductive area of a slot resonator, whereby the current concentration at the edges of the conductor opening serving as an inductive area can be mitigated to suppress the conductor loss. Further, by rendering the width and line interval of the conductor lines of the multi-step-ring resonant element equal to or less than the skin depth of the conductor and increasing the number of lines, the conductor loss due to the edge effect can entirely be reduced.
In the example shown in
Next, a structure of a filter according to a seventh embodiment of the present invention will be described with reference to FIGS. 13(A)-13(F).
A conductor layer 4 including four conductor openings AP1 to AP4 and two slits SL1 and SL2 is defined on the upper surface of a dielectric substrate 1. In this example, the pair of conductor openings AP3 and AP4 is larger than the pair of conductor openings AP1 and AP2 so as to provide 90-degree rotation asymmetry. Therefore, the frequencies of a mode in which magnetic field vectors are directed in the (x+y)-axis direction and a mode in which magnetic fields are directed in the (x−y)-axis direction differ, and a mode in which magnetic field vectors are directed in the x-axis direction and a mode in which magnetic field vectors are directed in the y-axis direction are coupled.
As in the illustration of
Inside the dielectric substrate 1, beneath the capacitance-forming conductor layer 5, there are provided capacitance-coupling electrodes 11a and 11b for generating a capacitance between the capacitance-coupling electrodes 11a and 11b and the capacitance-forming conductor layer 5, via-holes 10a and 10b brought into connection with the capacitance-coupling electrodes 11a and 11b, and input/output-coupling electrodes 9a and 9b brought into connection with the via-holes 10a and 10b.
An input/output terminal 8 brought into connection with the input/output-coupling electrode 9 is formed over the side surfaces and the bottom surface of the dielectric substrate 1. As shown in FIGS. 13(C) to 13(F), the capacitance-coupling electrode 11a is capacitively coupled to the capacitance-forming conductor layer 5 at a position displaced from the center of the capacitance-forming conductor layer 5 towards the x-axis direction, and the capacitance-coupling electrode 11b is capacitively coupled to the capacitance-forming conductor layer 5 at a position displaced from the center of the capacitance-forming conductor layer 5 towards the y-axis direction. Therefore, the input/output terminal 8a, the input/output-coupling electrode 9a, the via-hole 10a, and the capacitance-coupling electrode 11a are coupled to a resonant mode in which magnetic field vectors are directed in the y-axis direction. Likewise, the input/output terminal 8b, the input/output-coupling electrode 9b, the via-hole 10b, and the capacitance-coupling electrode 11b are coupled to a resonant mode in which magnetic field vectors are directed in the x-axis direction.
In FIGS. 6(A) and 7(A)-7(B), the directions in which the two slits SL1 and SL2 extend are denoted by the x- and y-axis directions. In the example shown in FIGS. 13(A)-13(F), however, the axes that lie in the plane perpendicular to a z-axis (the axis orthogonal to the x- and y axes) and that are rotated by 45 degrees with respect to the axes shown in FIGS. 6(A)-6(C) and 7(A)-7(B) are denoted by the x- and y-axes.
With this structure, the filter acts as a band-pass filter including the input/output terminals 8a and 8b serving as input/output units and a two-stage resonator.
FIGS. 14(A)-14(F) are diagrams showing a structure of a filter according to an eighth embodiment. What is different from the example shown in FIGS. 13(A)-13(F) is the section of input/output means. In the example shown in FIGS. 14(C)-14(E), an input/output-coupling electrode 9a extending in the x-axis direction from an input/output terminal 8a defined on a side surface of the dielectric substrate 1, and a via-hole 10a that extends in the z-axis direction from an end of the input/output-coupling electrode 9a and that is brought into connection with a shield electrode 7 defined on the bottom surface are provided. Further, an input/output-coupling electrode 9b extending in the y-axis direction from an input/output terminal 8b defined on another side surface of the dielectric substrate 1, and a via-hole lob that extends in the Z-axis direction from an end of the input/output-coupling electrode 9b and that is brought into connection with the shield electrode 7 defined on the bottom surface are provided. The input/output-coupling electrode 9a and the via-hole 10a, whose loop surfaces, together with the input/output terminal 8a, are parallel to the x-z plane, are magnetic-field coupled to a resonant mode in which magnetic field vectors are directed in the y-axis direction. The input/output-coupling electrode 9b and the via-hole 10b, whose loop surfaces, together with the input/output terminal 8b, are parallel to the y-z plane, are magnetic-field coupled to a resonant mode in which magnetic field vectors are directed in the x-axis direction.
With this structure, the filter acts as a band-pass filter including the input/output terminals 8a and 8b serving as input/output units and a two-stage resonator.
Next, a structure of an isolator according to a ninth embodiment will be described with reference to FIGS. 15(A)-15(F) and 21(A) to 23.
Inside a shield cap 14, a disk-shaped ferrite core 16 is placed on the top of a dielectric substrate 1 so as to be centered on the central portion of a region in which four conductor openings AP1 to AP4 are defined (the intersection of two slits SL1 and SL2 formed into a cross shape). The other portions are similar to those of the resonator shown in FIGS. 13(A)-13(F). Therefore, the frequencies of a mode in which magnetic field vectors are directed in the (x+y)-axis direction and a mode in which a magnetic field is directed in the (x-y)-axis direction differ, and two modes, i.e., a mode in which magnetic field vectors are directed in the x-axis direction and a mode in which magnetic field vectors are directed in the y-axis direction, are coupled. Since the directions of input/output-coupling electrodes 9a and 9b are orthogonal, the electromagnetic field generated by the two modes forms a circularly polarized wave in a region in which a capacitance-forming conductor layer 5 is defined (see
A direct-current magnetic field is applied to the ferrite core 16 from the outside in the direction perpendicular to the dielectric substrate 1 and the principal surface of the ferrite core 16 (by, for example, a permanent magnet placed outside the shield cap 14).
FIGS. 21(A)-21(C) illustrate a crossing angle of magnetic field vectors in two resonant modes that are degenerate.
FIGS. 22(A)-22(C) also illustrate a crossing angle of magnetic field vectors in two resonant modes.
μ+=μ+′+jμ+″
μ−=μ−′+jμ−″
When the magnetic field of the two modes generated by the signal input from the input/output terminal 8a passes through the ferrite core 16, the circularly polarized wave rotates in the direction in which the magnetic resonance absorption does not occur, in which case a signal is output to the input/output terminal 8b. Conversely, when the magnetic field of the two modes generated by the signal input from the input/output terminal 8b passes through the ferrite core 16, the circularly polarized wave rotates in the direction in which the magnetic resonance absorption occurs, and a signal is not output to the input/output terminal 8a. This arrangement therefore acts as an isolator.
FIGS. 16(A)-16(C) are diagrams showing a structure of an isolator according to a tenth embodiment.
A capacitance-forming conductor layer 5 is asymmetric with respect to the x- and y-axis directions. Therefore, the frequencies of the even mode and the odd mode shown in FIGS. 2(A)-2(B) differ, and the X mode in which the magnetic field vectors are entirely directed in the x-axis direction and the Y mode in which the magnetic field vectors are entirely directed in the y-axis direction are coupled (see FIGS. 3(A)-3(D)).
The slot SLL1 is coupled to the magnetic field of the X mode, and a signal propagates in the transmission mode of the slot line. The slot SLL2 is coupled to the magnetic field of the Y mode, and a signal propagates in the transmission mode of the slot line. This arrangement therefore acts as an isolator in which a signal can be input and output via slot lines.
FIGS. 17(A)-17(C) are diagrams showing a structure of an isolator according to an eleventh embodiment.
In this example, a slot SLL11 extending in the opposite direction to an AP1 direction from a conductor opening AP2 and a slot SLL12 extending along the slot SLL11 from the vicinity of the conductor opening AP2 are defined to form a coplanar guide. Likewise, a slot SLL21 extending in the opposite direction to an AP3 direction from a conductor opening AP4 and a slot SLL22 extending along the slot SLL21 from the vicinity of the conductor opening AP4 are defined to form a coplanar guide. This arrangement therefore acts as an isolator including the coplanar guides serving as input/output means.
FIGS. 18(A)-18(C) are diagrams showing a structure of an isolator according to a twelfth embodiment. In this example, a slot SLL11 extending in the opposite direction to an AP1 direction from a conductor opening AP2 and a slot SLL12 extending along the slot SLL11 from the vicinity of the conductor opening AP2 are defined to form a coplanar guide. Further, a slot SLL2 extending in the opposite direction to an AP3 direction from AP4 is defined. The other structure is similar to that shown in FIGS. 16(A)-16(C) and 17(A)-17(C). This arrangement therefore acts as an isolator including the coplanar guide serving as one input/output unit and the slot line serving as the other input/output unit.
FIGS. 19(A)-19(C) are diagrams showing a structure of an isolator according to a thirteenth embodiment. In this example, the shape of conductor openings AP1 to AP4 is substantially rectangular with four rounded corners. The resonant element 100 is not used. The other portions are similar to those shown in FIGS. 16(A)-16(C). Thus, the conductor openings may have any shape other than circular, and this arrangement also acts as an isolator.
FIGS. 20(A)-20(C) are diagrams showing a structure of an isolator according to a fourteenth embodiment.
Next, a structure of a communication communication apparatus according to a fifteenth embodiment of the present invention will be described with reference to
The filter with the structure illustrated in the above-described embodiments can be applied to any of the duplexer 123 and the band-pass filters 133, 136, and 139. The isolator with the structure illustrated in the above-described embodiments can be applied to the isolator 131.
Number | Date | Country | Kind |
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2003-377433 | Nov 2003 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP04/12260 | 8/26/2004 | WO | 5/5/2006 |