Patent Grant
11843154
This is a National Phase Application filed under 35 U.S.C. 371 as a national stage of PCT/CN2020/117852, filed Sep. 25, 2020, the content of which is hereby incorporated by reference in its entirety.
The present disclosure relates to the field of communication technology, and in particular to a balun assembly, a microwave radio frequency device, and an antenna.
A balun (i.e., balance-unbalance) assembly is a three-port (or three-terminal) device that may be applied to a microwave radio frequency device. The balun assembly is a radio frequency transmission line transformer that converts a matching input into a differential input, and may be used for exciting a differential line, an amplifier, a wideband antenna, a balanced mixer, a balanced frequency multiplier and modulator, a phase shifter, and any circuit design that requires transmission of signals with equal amplitudes and a phase difference of 180° on two lines. Here, two outputs of the balun assembly have equal amplitudes and opposite phases, which means that there is a phase difference of 180° between the two outputs in the frequency domain, and that a voltage of one balanced output is a negative value of a voltage of the other balanced output in the time domain.
The present disclosure aims to solve at least one of technical problems in the prior art and provides a balun assembly, a microwave radio frequency device, and an antenna.
In a first aspect, embodiments of the present disclosure provide a balun assembly, which includes:
In an embodiment, the first transmission electrode has a first signal end and a first open end opposite to each other, the second transmission electrode has a second signal end and a second open end opposite to each other, and the third transmission electrode has a third signal end and a third open end opposite to each other; and
In an embodiment, an orthographic projection of the second open end on the first substrate and an orthographic projection of the third open end on the first substrate are on a same side of the opening, a line length of the second transmission electrode from the second intersection point to the second signal end is L4, a line length of the third transmission electrode from the third intersection point to the third signal end is L5, and the line lengths L5 and L4 have a difference of ½ of a medium wavelength therebetween.
In an embodiment, a portion of the third transmission electrode from the third intersection point to the third signal end includes a serpentine line.
In an embodiment, an orthographic projection of the first transmission electrode on the first substrate, an orthographic projection of the second transmission electrode on the first substrate, and an orthographic projection of the third transmission electrode on the first substrate overlap each other.
In an embodiment, an orthographic projection of the second open end on the first substrate and an orthographic projection of the third open end on the first substrate are on both sides of the opening, respectively, a line length of the second transmission electrode from the second intersection point to the second signal end is L4, a line length of the third transmission electrode from the third intersection point to the third signal end is L5, and the line lengths L4 and L5 are substantially equal to each other.
In an embodiment, each of the first transmission electrode, the second transmission electrode, and the third transmission electrode includes a serpentine line.
In an embodiment, the balun assembly further includes a second substrate opposite to the first dielectric layer and at a side of the first dielectric layer distal to the ground electrode, both the second transmission electrode and the third transmission electrode are on the first dielectric layer, and a second dielectric layer is between a layer where the second transmission electrode and third transmission electrode are located and the second substrate.
In an embodiment, the balun assembly further includes a second substrate opposite to the first dielectric layer and at a side of the first dielectric layer distal to the ground electrode;
In an embodiment, the second dielectric layer includes a liquid crystal layer.
In an embodiment, a width of the opening in an extension direction of the opening ranges from ¼ of a medium wavelength to ½ of the medium wavelength.
In a second aspect, embodiments of the present disclosure provide a microwave radio frequency device, which including the balun assembly according to any one of foregoing embodiments.
In an embodiment, the microwave radio frequency device includes a phase shifter or a filter.
In a third aspect, embodiments of the present disclosure provide an antenna, which includes the microwave radio frequency device according to any one of foregoing embodiments.
To enable one of ordinary skill in the art to better understand technical solutions of the present disclosure, the present disclosure will be further described in detail below with reference to the accompanying drawings and exemplary embodiments.
Unless defined otherwise, technical or scientific terms used herein should have the ordinary meaning as understood by one of ordinary skill in the art to which the present disclosure belongs. The terms of “first”, “second”, and the like used in the present disclosure are not intended to indicate any order, quantity, or importance, but rather are used for distinguishing one element from another. Further, the terms “a”, “an”, “the”, or the like do not denote a limitation of quantity, but rather denote the presence of at least one element. The term of “comprising”, “including”, or the like, means that the element or item preceding the term contains the element or item listed after the term and its equivalent, but does not exclude the presence of other elements or items. The term “connected”, “coupled”, or the like is not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect connections. The terms “upper”, “lower”, “left”, “right”, and the like are used merely for indicating relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.
As described above, a balun (i.e., balance-unbalance) assembly is a three-port (or three-terminal) device that may be applied to a microwave radio frequency device. The balun assembly is a radio frequency transmission line transformer that converts a matching input into a differential input, and may be used for exciting a differential line, an amplifier, a wideband antenna, a balanced mixer, a balanced frequency multiplier and modulator, a phase shifter, and any circuit design that requires transmission of signals with equal amplitudes and a phase difference of 180° on two lines. Here, two outputs of the balun assembly have equal amplitudes and opposite phases, which means that there is a phase difference of 180° between the two outputs in the frequency domain, and that a voltage of one balanced output is a negative value of a voltage of the other balanced output in the time domain.
It should be noted that, in an embodiment of the present disclosure, description will be made by taking an example in which a microwave radio frequency device is a phase shifter, but it should be understood that an embodiment of the present disclosure is not limited to the example in which the microwave radio frequency device is the phase shifter.
In an example, the phase shifter includes not only a balun assembly, but also a phase shifting structure.
In the related art, when a microwave signal is input to a phase shifter via a balun structure, the balun structure is generally connected to the phase shifter in a welding (direct) manner for feeding. For this manner, there are two mechanisms of applying a frame sealant on a thick copper wire (i.e., a transmission line): {circle around (1)} for a straight-through balun structure, it needs the frame sealant to be provided between a balun output terminal and a phase shifting section of the phase shifter to separate them from each other, and {circle around (2)} the welded transmission line needs to penetrate through the frame sealant so as to extend to an edge of a welding pad. During a manufacturing process of a liquid crystal phase shifter, the problems of sealant breakage, nonuniformity thickness of a cell, liquid leakage, and the like may occur due to applying the frame sealant on the thick copper wire. In view of the problems of the existing balun structure that feeds power in the welding (direct) manner, embodiments of the present disclosure provide technical solutions as follows. In a first aspect, an embodiment of the present disclosure provides a balun assembly, which includes: a first substrate 100, a first dielectric layer 300, a first transmission electrode 11, a second transmission electrode 21, a third transmission electrode 22, and a ground electrode 12. For example, the first substrate 100 has a first surface and a second surface opposite to each other. The first transmission electrode 11 is disposed on the first surface of the first substrate 100. The ground electrode 12 has an opening 121 therein, and is disposed on a side (i.e., the second surface) of the first substrate 100 distal to the first surface. The first dielectric layer 300 is disposed on a side of the ground electrode 12 distal to the first substrate 100. The second transmission electrode 21 and the third transmission electrode 22 are disposed on a side of the first dielectric layer 300 distal to the ground electrode 12. Each of an orthographic projection of the first transmission electrode 11 on the first substrate 100, an orthographic projection of the second transmission electrode 21 on the first substrate 100, and an orthographic projection of the third transmission electrode 22 on the first substrate 100 intersects with an orthographic projection of the opening 121 on the first substrate 100, and intersection points of the orthographic projection of the first transmission electrode 11 on the first substrate 100, the orthographic projection of the second transmission electrode 21 on the first substrate 100, and the orthographic projection of the third transmission electrode 22 on the first substrate 100 intersecting with the orthographic projection of the opening 121 on the first substrate are a first intersection point N1, a second intersection point N2, and a third intersection point N3, respectively. The first intersection point N1 is located between the second intersection point N2 and the third intersection point N3.
It should be noted that the “intersection point” in an embodiment of the present disclosure may refer to a region where two orthographic projections intersect each other, and the region may be a point or may have a certain area. For example, the first intersection point N1 of the orthographic projections of the opening 121 and the first transmission electrode 11 on the first substrate 100 is a rectangular region having a certain area.
In the present embodiment, the ground electrode 12 is disposed between the first substrate where the first transmission electrode 11 is located and the first dielectric layer 300 where the second transmission electrode 21 and the third transmission electrode 22 are located, the ground electrode 12 has the opening 121 therein, intersection points of the orthographic projections of the first transmission electrode 11, the second transmission electrode 21 and the third transmission electrode 22 on the first substrate 100 intersecting with the orthographic projection of the opening 121 on the first substrate are the first intersection point N1, the second intersection point N2, and the third intersection point N3, respectively, and the first intersection point N1 is located between the second intersection point N2 and the third intersection point N1 As such, a microwave signal transmitted on the first transmission electrode 11 is respectively coupled, by an electromagnetic coupling effect, to the second transmission electrode 21 and the third transmission electrode 22 through the opening 121 of the ground electrode 12, so as to be transmitted. That is, in the balun structure (i.e., the balun assembly) provided by the present embodiment, the first transmission electrode 11, the second transmission electrode 21, and the third transmission electrode 22 transmit the microwave signal in a coupling manner. Compared with the welding connection feeding scheme in the related art, the balun structure according to the present embodiment has a higher feeding efficiency and a reflection bandwidth up to about 15%, and can achieve a phase difference of 180°.
In an example,
It should be noted that, the medium wavelength refers to a wavelength of an electromagnetic wave in a medium, and is related to a permittivity (which may be also referred to as a dielectric constant) of the medium. The expression that each of the line lengths L1, L2 and L3 is substantially equal to ¼ of the medium wavelength means that, each of the line lengths L1, L2 and L3 is equal to ¼ of the medium wavelength, or is equal to ¼ of the medium wavelength plus or minus an error value which may be defined according to an accuracy requirement of the balun assembly.
Referring to
In another example,
It should be noted that, the expression that each of the line lengths L1, L2 and L3 is substantially equal to ¼ of the medium wavelength means that, each of the line lengths L1, L2 and L3 is equal to ¼ of the medium wavelength, or is equal to ¼ of the medium wavelength plus or minus an error value which may be defined according to an accuracy requirement of the balun assembly. Further, in a case where the distance between the intersection points N1 and N2 is equal to the distance between the intersection points N1 and N3, the impedance Z1 of the first transmission electrode 11 is slightly greater than the parallel impedance Z2 of the second transmission electrode 21 and the third transmission electrode 22, thereby achieving better power distribution. If a difference between the distance between the intersection points N1 and N2 and the distance between the intersection points N1 and N3 is smaller, it may be necessary that a difference between the impedance Z1 of the first transmission electrode 11 and the parallel impedance Z2 of the second transmission electrode 21 and the third transmission electrode 22 is larger to achieve distribution of equal powers.
Referring to
It should be noted that, although a structure of only one exemplary reverse (or backward) coupling balun assembly is described above, the present disclosure is not limited thereto. For example, the present disclosure may include the reverse balun assembly having any structure in which the orthographic projections of the second open end c2 of the second transmission electrode 21 and the third open end c3 of the third transmission electrode 22 on the first substrate 100 are located on different sides of the opening 121, respectively.
For example, in the forward coupling balun assembly or the reverse coupling balun assembly, the second transmission electrode 21 and the third transmission electrode 22 may be disposed in a same layer, or in different layers, respectively. Exemplary structures in which the second transmission electrode 21 and the third transmission electrode 22 are disposed in a same layer and are disposed in different layers, respectively, will be described below.
It should be noted that in
When the balun assembly according to an embodiment of the present disclosure is applied to a phase shifter, the first base plate 10 of the phase shifting structure and the first dielectric layer 300 may be a one-piece structure, the second substrate 200 and the second base plate may be a one-piece structure, and a liquid crystal layer 3 of the balun assembly and the liquid crystal layer 3 of the phase shifting structure may be a one-piece structure. Further, the second transmission electrode 21 and the first transmission line 1 may be a one-piece structure, the third transmission electrode 22 and the second transmission line 2 may be a one-piece structure, and the ground electrode 12 and the ground electrode 4 may be a one-piece structure. As such, the manufacturing cost of the phase shifter may not be increased.
In addition, it should be noted that the shapes of the second transmission electrode 21 and the third transmission electrode 22 in
In some embodiments, each of the first transmission electrode 11, the second transmission electrode 21, and the third transmission electrode 22 includes a microstrip, and the ground electrode 12 includes the ground electrode 4. A material of each of the first transmission electrode 11, the second transmission electrode 21, the third transmission electrode 22, and the ground electrode 12 may include a metal such as copper, aluminum, silver, gold, chromium, molybdenum, nickel, iron, or the like.
In some embodiments, the opening 121 in the ground electrode 12 has a shape of a rectangle, but an embodiment of the present disclosure is not limited thereto. For example, the opening 121 in the ground electrode 12 may alternatively have any another shape.
In some embodiments, each of the first dielectric layer 300, the first substrate 100, and the second substrate 200 may be a glass substrate with a thickness of 100 microns to 1000 microns, or may be a sapphire substrate, or may be a polyethylene terephthalate substrate, a triallyl cyanurate substrate or a transparent flexible polyimide substrate, which has a thickness of 10 microns to 500 microns. Alternatively, each of the first dielectric layer 300, the first substrate 100, and the second substrate 200 may be made of high-purity quartz glass having extremely low dielectric loss. Compared with a general glass substrate, the first dielectric layer 300, the first substrate 100 and the second substrate 200 made of the quartz glass can effectively reduce a loss of a microwave, such that the phase shifter have low power consumption and a high signal-to-noise ratio.
For example, liquid crystal molecules of the liquid crystal layer 3 may be positive liquid crystal molecules or negative liquid crystal molecules. It should be noted that, in a case where the liquid crystal molecules are the positive liquid crystal molecules, an angle between a long axis direction of each liquid crystal molecule and the second transmission electrode according to an embodiment of the present disclosure is greater than zero and less than or equal to 45°. In a case where the liquid crystal molecules are the negative liquid crystal molecules, the angle between the long axis direction of each liquid crystal molecule and the second transmission electrode is greater than 45° and less than 90°. As such, it is ensured that the permittivity (i.e., the dielectric constant) of the liquid crystal layer 3 is changed after the liquid crystal molecules are caused to rotate, thereby achieving the purpose of phase shifting.
In a second aspect, the embodiments of the present disclosure further provide a microwave radio frequency device including the balun assembly according to any one of the foregoing embodiments, and the microwave radio frequency device may include, but is not limited to, a filter or a phase shifter.
In a third aspect, the embodiments of the present disclosure further provide a liquid crystal antenna, which includes the phase shifter according to any one of the foregoing embodiments. For example, at least two patch units are further disposed on a side of the second base plate 20 distal to the liquid crystal layer 3, and a gap between any adjacent two of the patch units is provided corresponding to a gap between electrode strips. In this way, a microwave signal phase-adjusted by the phase shifter according to any one of the foregoing embodiments can be radiated from the gap between any adjacent two of the patch elements.
It should be understood that the foregoing embodiments are merely exemplary embodiments adopted to explain the principles of the present disclosure, and the present disclosure is not limited thereto. It will be apparent to one of ordinary skill in the art that various modifications and improvements can be made without departing from the spirit and scope of the present disclosure, and such modifications and improvements also fall within the scope of the present disclosure.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2020/117852 | 9/25/2020 | WO |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2022/061746 | 3/31/2022 | WO | A |
| Number | Date | Country | |
|---|---|---|---|
| 20220311115 A1 | Sep 2022 | US |
