A low-loss duplexer for D-band

Abstract

The present application relates to the field of signal transmission technology, and in particular to a low-loss duplexer for use in the D band. The low-loss duplexer includes a stacked cover plate and a base plate; the surface of the base plate facing the cover plate is concave to form a waveguide cavity, and the inside of the waveguide cavity is enclosed by metal pillars to form a T-shaped power divider and two coupled resonant filters, and the coupled resonant filters are relatively arranged at the two ends of the horizontal side of the T-shaped power divider; the surface of the base plate facing away from the cover plate is provided with an antenna port corresponding to the position of the vertical side of the T-shaped power divider, and the side of the base plate is provided with a transmitting port and a receiving port corresponding to the position of the coupled resonant filter away from the end of the T-shaped power divider; the opposite surfaces of the cover plate and the base plate cooperate to form a right-angle coupling structure and two signal transmission channels, the T-shaped power divider is connected to the antenna port through the right-angle coupling structure, and the coupled resonant filter is connected to the corresponding port through the signal transmission channel. The present application has the advantages of high isolation, low conductor loss, low cost, and easy mass production.

Description

Technical Field

[0001] The present application relates to the technical field of signal transmission, and in particular to a low-loss duplexer for D-band. Background Art

[0002] With the rapid development of wireless communication networks, the demand for large communication capacity and high-speed communication services is increasing. Traditional microwave bands (such as L-band, S-band, C-band, X-band, Ku-band, K-band and Ka-band) are approaching saturation, while the D-band (110-170 GHz) has a bandwidth of 60 GHz and has broad application prospects in the field of high-speed wireless communications.

[0003] The duplexer is an important component of the RF front end of the wireless communication system, which is used to separate the transmit and receive signals and transmit the receive and transmit circuit signals to the antenna. The traditional duplexer is realized by classical waveguide technology (i.e., transmitting electromagnetic waves by reflection of the metal wall inside the waveguide). This technology has low insertion loss in traditional microwave band applications, but in millimeter wave band applications (such as V-band, W-band and D-band), there are problems such as large size, high conductor loss and high production cost. Summary of the invention

[0004] In view of the above-mentioned problems, the present application is proposed to provide a low-loss duplexer for D-band that overcomes the problems or at least partially solves the problems, comprising:

[0005] A low-loss duplexer for D-band, comprising a cover plate and a bottom plate arranged in a stacked manner;

[0006] The surface of the bottom plate facing the cover plate is concave to form a waveguide cavity, the inside of the waveguide cavity is surrounded by metal pillars to form a T-shaped power divider and two coupled resonant filters, and the coupled resonant filters are relatively arranged at two ends of the horizontal side of the T-shaped power divider;

[0007] An antenna port is provided on the surface of the base plate facing away from the cover plate, corresponding to the position of the vertical side of the T-shaped power divider, and a transmitting port and a receiving port are respectively provided on the side of the base plate, corresponding to the position of the coupled resonant filter away from the end of the T-shaped power divider; the opposite surfaces of the cover plate and the base plate cooperate to form a right-angle coupling structure and two signal transmission channels, the T-shaped power divider is connected to the antenna port through the right-angle coupling structure, the coupled resonant filter corresponding to the position of the transmitting port is connected to the transmitting port through one of the signal transmission channels, and the coupled resonant filter corresponding to the position of the receiving port is connected to the receiving port through another of the signal transmission channels.

[0008] Preferably, it also includes a first flange arranged at the antenna port, a second flange arranged at the transmitting port and a third flange arranged at the receiving port; the antenna port is connected to the antenna through the first flange, the transmitting port is connected to the transmitter through the second flange, and the receiving port is connected to the receiver through the third flange.

[0009] Preferably, the interior of the waveguide cavity is enclosed by metal pillars to form a metal fence, and the metal fence is arranged at the end of the vertical side of the T-shaped power divider; a signal through hole extending from the antenna port to the vertical side of the T-shaped power divider is provided inside the base plate; a metal bump is provided on the surface of the cover plate facing the base plate at a position corresponding to the signal through hole; the right-angle coupling structure is formed by the cooperation of the signal through hole, the metal fence and the metal bump.

[0010] Preferably, metal walls are respectively provided inside the waveguide cavity corresponding to the positions of the coupled resonant filter away from the end of the T-shaped power divider, and the metal walls include two metal bars arranged in parallel with the extension direction of the coupled resonant filter, and the metal bars are at the same height as the top of the base plate; signal grooves are respectively provided on the surface of the base plate facing the cover plate corresponding to the positions of the metal walls away from the end of the coupled resonant filter, and the depth of the signal grooves is greater than the depth of the waveguide cavity, one of the signal grooves extends from the metal walls at the corresponding position to the transmitting port, and the other signal groove extends from the metal walls at the corresponding position to the receiving port; the signal transmission channel is formed by the cooperation of the metal walls, the signal grooves and the cover plate.

[0011] Preferably, each of the coupled resonator filters comprises five resonant cavities.

[0012] Preferably, the height of the metal pillar is 1 / 4 of the operating wavelength.

[0013] Preferably, the center distance between adjacent metal pillars is less than 1 / 2 of the operating wavelength.

[0014] Preferably, the air gap between the metal pillar and the cover plate is 0.03 mm.

[0015] Preferably, the surfaces of the cover plate and the metal pillar are respectively provided with a silver coating.

[0016] Preferably, the cover plate and the base plate are connected by screws.

[0017] This application has the following advantages:

[0018] In the embodiments of the present application, in contrast to the problems of the existing duplexers with large size, high conductor loss and high production cost, the present application provides a solution to the duplexer based on slotted gap waveguides, specifically: "A low-loss duplexer for D band, comprising a cover plate and a bottom plate arranged in layers; the surface of the bottom plate facing the cover plate is concave to form a waveguide cavity, the inside of the waveguide cavity is surrounded by metal pillars to form a T-shaped power divider and two coupled resonant filters, the coupled resonant filters are relatively arranged at the two ends of the horizontal side of the T-shaped power divider; the surface of the bottom plate facing away from the cover plate corresponds to the vertical side of the T-shaped power divider. An antenna port is provided at the position of the straight edge, and a transmitting port and a receiving port are respectively provided at the side of the bottom plate corresponding to the position of the coupled resonant filter away from the end of the T-shaped power divider; the opposite surfaces of the cover plate and the bottom plate cooperate to form a right-angle coupling structure and two signal transmission channels, the T-shaped power divider is connected to the antenna port through the right-angle coupling structure, the coupled resonant filter corresponding to the position of the transmitting port is connected to the transmitting port through one of the signal transmission channels, and the coupled resonant filter corresponding to the position of the receiving port is connected to the receiving port through another of the signal transmission channels.

[0019] By designing a slotted gap waveguide duplexer including a T-shaped power divider, two coupled resonant filters, a right-angle coupling structure of a slotted gap waveguide to a rectangular waveguide transition, and two signal transmission channels of a slotted gap waveguide to a rectangular waveguide transition, the slotted gap waveguide structure is compact, and the size of the duplexer can be significantly reduced while maintaining high performance, which is suitable for the miniaturization requirements of high-frequency systems; and the slotted gap waveguide optimizes the electromagnetic field distribution so that the electromagnetic field is mainly concentrated in the air gap, reducing the distribution of the electromagnetic field on the conductor surface, thereby significantly reducing the conductor loss and improving the signal transmission efficiency. At the same time, due to the open structure, ventilation and cooling are allowed, so that the duplexer is less sensitive to temperature drift; in addition, the slotted gap waveguide structure avoids the vacuum welding and diffusion welding processes of the traditional waveguide structure, which can simplify the manufacturing process and reduce the production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the description of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 It is a schematic diagram of the overall structure of a low-loss duplexer provided in one embodiment of the present application;

[0022] Figure 2This is a schematic structural diagram of a surface of a cover plate facing a base plate in a low-loss duplexer provided in an embodiment of the present application;

[0023] Figure 3 It is a partial structural schematic diagram of the surface of the cover plate facing the base plate in the low-loss duplexer provided in one embodiment of the present application;

[0024] Figure 4 This is a schematic structural diagram of a surface of a bottom plate facing a cover plate in a low-loss duplexer provided in an embodiment of the present application;

[0025] Figure 5 This is a schematic structural diagram of the surface of the bottom plate facing away from the cover plate in the low-loss duplexer provided in one embodiment of the present application;

[0026] Figure 6 It is a schematic diagram of the partial structure of the surface of the bottom plate facing away from the cover plate in the low-loss duplexer provided in one embodiment of the present application;

[0027] Figure 7 It is a structural schematic diagram of a T-shaped power divider in a low-loss duplexer provided in an embodiment of the present application;

[0028] Figure 8 It is a structural schematic diagram of a coupled resonant filter in a low-loss duplexer provided in an embodiment of the present application;

[0029] Fig. 9 It is a structural schematic diagram of a right-angle coupling structure in a low-loss duplexer provided in an embodiment of the present application;

[0030] Fig.10 It is a structural schematic diagram of a signal transmission channel in a low-loss duplexer provided in an embodiment of the present application;

[0031] Fig.11 is a graph showing the variation of the S11 parameters of the cover plate and the base plate with the frequency in the low-loss duplexer provided in one embodiment of the present application;

[0032] Fig.12 is a graph showing the variation of S11 parameter and S12 parameter of a T-shaped power divider in a low-loss duplexer provided in an embodiment of the present application with frequency;

[0033] Fig.13 is a graph showing the variation of the simulated and measured S parameters of the coupled resonant filter in the low-loss duplexer provided in one embodiment of the present application with the frequency;

[0034] Fig.14 It is a curve diagram showing the simulated and measured S parameters of a low-loss duplexer provided in an embodiment of the present application as a function of frequency.

[0035] The reference numerals in the drawings of the specification are as follows:

[0036] 10. Cover plate; 20. Bottom plate; 201. Waveguide cavity; 202. Metal pillar; 203. Metal ridge; 21. T-shaped power divider; 22. Coupled resonant filter; 23. Antenna port; 24. Transmitting port; 25. Receiving port; 30. Right-angle coupling structure; 301. Signal via; 302. Metal fence; 303. Metal bump; 40. Signal transmission channel; 401. Metal fence; 402. Signal groove. DETAILED DESCRIPTION

[0037] In order to make the objects, features and advantages of the present application more obvious and understandable, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0038] The inventors found through analyzing the prior art that traditional duplexers rely on classical waveguide technology. The physical size of the waveguide is a function of the wavelength. As the frequency increases, the size of the waveguide will decrease in some dimensions. However, under the premise of maintaining good performance, a certain amount of space is still required to achieve effective signal transmission and isolation, resulting in a large size of the duplexer, which is not conducive to connecting to the electronic circuits on the printed circuit board; and as the frequency increases, the current concentration effect (skin effect) causes the current to be more concentrated in the thin layer on the surface of the conductor, the effective transmission cross-section of the conductor is significantly reduced, and the resistance is significantly increased, resulting in higher conductor loss in the duplexer; in addition, traditional duplexers require high-precision vacuum welding and diffusion welding processes to prevent signal leakage inside the waveguide. This process flow is relatively complicated and also increases production costs.

[0039] Reference Figure 1-Figure 10 , shows a low-loss duplexer for D-band provided by an embodiment of the present application, comprising a cover plate 10 and a base plate 20 which are stacked;

[0040] The surface of the bottom plate 20 facing the cover plate 10 is concave to form a waveguide cavity 201, and the inside of the waveguide cavity 201 is surrounded by metal pillars 202 to form a T-shaped power divider 21 and two coupled resonant filters 22, and the coupled resonant filters 22 are relatively arranged at two ends of the horizontal side of the T-shaped power divider 21;

[0041] An antenna port 23 is provided on the surface of the base plate 20 facing away from the cover plate 10, corresponding to the position of the vertical side of the T-shaped power divider 21, and a transmitting port 24 and a receiving port 25 are respectively provided on the side of the base plate 20, corresponding to the position of the coupled resonant filter 22 away from the end of the T-shaped power divider 21; the opposite surfaces of the cover plate 10 and the base plate 20 cooperate to form a right-angle coupling structure 30 and two signal transmission channels 40, the T-shaped power divider 21 is connected to the antenna port 23 through the right-angle coupling structure 30, the coupled resonant filter 22 corresponding to the position of the transmitting port 24 is connected to the transmitting port 24 through one of the signal transmission channels 40, and the coupled resonant filter 22 corresponding to the position of the receiving port 25 is connected to the receiving port 25 through another of the signal transmission channels 40.

[0042] By designing a slotted gap waveguide duplexer including a T-shaped power divider 21, two coupled resonant filters 22, a right-angle coupling structure 30 for transition from a slotted gap waveguide to a rectangular waveguide, and a signal transmission channel 40 for transition from two slotted gap waveguides to rectangular waveguides, the slotted gap waveguide structure is compact, and the size of the duplexer can be significantly reduced while maintaining high performance, so that it is suitable for the miniaturization requirements of high-frequency systems; and the slotted gap waveguide optimizes the electromagnetic field distribution so that the electromagnetic field is mainly concentrated in the air gap, reducing the distribution of the electromagnetic field on the conductor surface, thereby significantly reducing the conductor loss and improving the signal transmission efficiency. At the same time, due to the open structure, ventilation and cooling are allowed, so that the duplexer is less sensitive to temperature drift; in addition, the slotted gap waveguide structure avoids the vacuum welding and diffusion welding processes of the traditional waveguide structure, which can simplify the manufacturing process and reduce the production cost.

[0043] Next, the low-loss duplexer in this exemplary embodiment will be further described.

[0044] In this embodiment, it also includes a first flange arranged at the antenna port 23, a second flange arranged at the transmitting port 24, and a third flange arranged at the receiving port 25; the antenna port 23 is connected to the antenna through the first flange, the transmitting port 24 is connected to the transmitter through the second flange, and the receiving port 25 is connected to the receiver through the third flange.

[0045] The first flange, the second flange and the third flange are all rectangular waveguide connectors. As an example, the first flange, the second flange and the third flange are WR-7 flanges respectively. The right-angle coupling structure 30 and the signal transmission channel 40 can achieve a smooth transition from a rectangular waveguide to a slotted gap waveguide through structural gradient (for example, gradually changing the structural size, using a gradient transition section, etc.) and impedance matching design, thereby reducing signal reflection and transmission loss and improving overall transmission efficiency.

[0046] In this embodiment, the interior of the waveguide cavity 201 is enclosed by metal pillars 202 to form a metal fence 302, and the metal fence 302 is arranged at the end of the vertical side of the T-shaped power divider 21; the interior of the base plate 20 is provided with a signal through hole 301 extending from the antenna port 23 to the vertical side of the T-shaped power divider 21; the surface of the cover plate 10 facing the base plate 20 is provided with a metal bump 303 at a position corresponding to the signal through hole 301; the right-angle coupling structure 30 is formed by the signal through hole 301, the metal fence 302 and the metal bump 303.

[0047] In this embodiment, metal walls 401 are respectively provided inside the waveguide cavity 201 corresponding to the positions of the coupled resonant filter 22 away from the end of the T-shaped power divider 21, and the metal walls 401 include two metal bars arranged in parallel with the extension direction of the coupled resonant filter 22, and the metal bars are at the same height as the top of the base plate 20; signal grooves 402 are respectively provided on the surface of the base plate 20 facing the cover plate 10 corresponding to the positions of the metal walls 401 away from the end of the coupled resonant filter 22, and the depth of the signal grooves 402 is greater than the depth of the waveguide cavity 201, one of the signal grooves 402 extends from the metal walls 401 at the corresponding position to the transmitting port 24, and the other signal groove 402 extends from the metal walls 401 at the corresponding position to the receiving port 25; the signal transmission channel 40 is formed by the metal walls 401, the signal grooves 402 and the cover plate 10.

[0048] In this embodiment, each of the coupled resonant filters 22 includes five resonant cavities. As an example, each of the coupled resonant filters 22 is formed by a plurality of metal pillars 202 enclosed on both sides of ten equally spaced metal ridges 203, wherein every two adjacent metal ridges 203 and the metal pillars 202 at corresponding positions enclose one resonant cavity, and the five resonant cavities are equally spaced along the extension direction of the coupled resonant filter 22, and the metal ridges 203 are arranged in the middle of the metal pillars 202 on both sides to control the coupling between the resonant cavities. Through the cascading of multiple resonant cavities, the coupled resonant filter 22 can achieve a steeper passband edge and better out-of-band suppression effect.

[0049] In this embodiment, the height of the metal pillar 202 is 1 / 4 of the operating wavelength. As an example, the height of the metal pillar 202 is 0.6 mm. The height of 1 / 4 wavelength makes the metal pillar 202 exhibit strong electromagnetic resonance at a specific frequency, which helps to form a high impedance surface, thereby effectively simulating the characteristics of an artificial magnetic conductor.

[0050] In this embodiment, the center distance between adjacent metal pillars 202 is less than 1 / 2 of the operating wavelength. As an example, the center distance between adjacent metal pillars 202 is 0.8 mm. The spacing less than 1 / 2 wavelength ensures that the periodic structure formed by the pillar array can effectively suppress the propagation of surface waves, because the denser arrangement can enhance the coupling of electromagnetic waves between the pillars, thereby improving the surface impedance characteristics of the waveguide. This design can also increase the bandwidth of the system, so that the waveguide has good transmission characteristics in a wider frequency range.

[0051] In this embodiment, the air gap between the metal pillars 202 and the cover plate 10 is 0.03 mm. The air gap of 0.03 mm is small, which can enhance the confinement of electromagnetic waves between the metal pillars 202 and reduce energy leakage.

[0052] In this embodiment, a silver coating is provided on the surface of the cover plate 10 and the metal pillar 202. Silver has an extremely low resistivity, and by providing a silver coating on the surface of the cover plate 10 and the metal pillar 202, the power loss caused by the surface current can be reduced, thereby reducing the insertion loss of the duplexer.

[0053] In this embodiment, the cover plate 10 and the bottom plate 20 are connected by screws. The upper and lower metal plates are assembled by screwing, avoiding the vacuum welding and diffusion welding process of the traditional waveguide structure, making the duplexer production cost low and easy to mass produce.

[0054] The performance test results of the low-loss duplexer are as follows:

[0055] Fig.11 The graphs showing the S11 parameters of the cover plate 10 (i.e., the via cover plate) and the bottom plate 20 (i.e., the via needle plate) as a function of frequency are shown. It can be seen that the return loss of the via cover plate is substantially lower than -20 dB in the range of 130 GHz to 160 GHz, and the return loss of the via needle plate is substantially lower than -20 dB in the range of 136 GHz to 154 GHz.

[0056] Fig.12 The graphs showing the S11 and S12 parameters of the T-shaped power divider 21 as a function of frequency show that the return loss is substantially lower than -20 dB in the range of 134 GHz to 152 GHz.

[0057] Fig.13 Graphs of simulated and measured S-parameters of the coupled resonator filter 22 as a function of frequency are shown.

[0058] Fig.14The simulated and measured S-parameters of the low-loss duplexer are plotted against frequency. It can be seen that the return loss of the receive and transmit bands is substantially lower than -15 dB; in addition, the isolation between the two bands is substantially lower than -60 dB.

[0059] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present application.

[0060] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.

[0061] The above is a detailed introduction to a low-loss duplexer for the D-band provided by the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A low-loss duplexer for D-band, characterized in that: It comprises a cover plate and a bottom plate which are stacked; the cover plate and the bottom plate are connected to form a rectangular waveguide structure; The surface of the bottom plate facing the cover plate is concave to form a waveguide cavity, the inside of the waveguide cavity is surrounded by metal pillars to form a T-shaped power divider and two coupled resonant filters, and the coupled resonant filters are relatively arranged at two ends of the horizontal side of the T-shaped power divider; An antenna port is provided on the surface of the bottom plate facing away from the cover plate, corresponding to the position of the vertical side of the T-shaped power divider, and a transmitting port and a receiving port are respectively provided on the side of the bottom plate, corresponding to the position of the coupled resonant filter away from the end of the T-shaped power divider; the opposite surfaces of the cover plate and the bottom plate cooperate to form a right-angle coupling structure and two signal transmission channels, the T-shaped power divider is connected to the antenna port through the right-angle coupling structure, the coupled resonant filter corresponding to the position of the transmitting port is connected to the transmitting port through one of the signal transmission channels, and the coupled resonant filter corresponding to the position of the receiving port is connected to the receiving port through another of the signal transmission channels; Each of the coupled resonant filters is formed by a plurality of metal pillars enclosed on both sides of ten metal ridges arranged at equal intervals, wherein every two adjacent metal ridges and the metal pillars at corresponding positions enclose a resonant cavity, the resonant cavities are arranged at equal intervals along the extension direction of the coupled resonant filter, and the metal ridges are arranged in the middle of the metal pillars on both sides to control the coupling between the resonant cavities; The inside of the waveguide cavity is surrounded by metal pillars to form a metal fence, and the metal fence is arranged at the end of the vertical side of the T-shaped power divider; the inside of the bottom plate is provided with a signal through hole extending from the antenna port to the vertical side of the T-shaped power divider; the surface of the cover plate facing the bottom plate is provided with a metal bump at a position corresponding to the signal through hole; the right-angle coupling structure is formed by the signal through hole, the metal fence and the metal bump; Metal walls are provided inside the waveguide cavity corresponding to the positions of the coupled resonant filter away from the end of the T-shaped power divider, and the metal walls include two metal bars arranged in parallel with the extension direction of the coupled resonant filter, and the metal bars are at the same height as the top of the bottom plate; signal grooves are provided on the surface of the bottom plate facing the cover plate corresponding to the positions of the metal walls away from the end of the coupled resonant filter, and the depth of the signal grooves is greater than the depth of the waveguide cavity, one of the signal grooves extends from the metal walls at the corresponding position to the transmitting port, and the other signal groove extends from the metal walls at the corresponding position to the receiving port; the signal transmission channel is formed by the cooperation of the metal walls, the signal grooves and the cover plate.

2. The low-loss duplexer according to claim 1, characterized in that: It also includes a first flange arranged at the antenna port, a second flange arranged at the transmitting port, and a third flange arranged at the receiving port; the antenna port is connected to the antenna through the first flange, the transmitting port is connected to the transmitter through the second flange, and the receiving port is connected to the receiver through the third flange.

3. The low-loss duplexer according to claim 1, characterized in that: The height of the metal pillar is 1 / 4 of the operating wavelength.

4. The low-loss duplexer according to claim 1, characterized in that: The center distance between adjacent metal pillars is less than 1 / 2 of the operating wavelength.

5. The low-loss duplexer according to claim 1, characterized in that: The air gap between the metal pillar and the cover plate is 0.03 mm.

6. The low-loss duplexer according to claim 1, characterized in that: The surfaces of the cover plate and the metal pillar are respectively provided with silver plating layers.

7. The low-loss duplexer according to claim 1, characterized in that: The cover plate and the bottom plate are connected by screws.

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