A millimeter wave gap waveguide duplexer based on a hybrid cavity structure

Abstract

The application provides a millimeter wave gap waveguide duplexer based on a mixed cavity structure, which comprises, from top to bottom, an upper metal cover plate, an intermediate metal block and a lower metal cover plate; the upper metal cover plate is provided with a coaxial input port; the lower metal cover plate is provided with a first coaxial output port and a second coaxial output port; the upper surface and the lower surface of the intermediate metal block are provided with a first periodic metal pin array and a second periodic metal pin array; the first periodic metal pin array and the second periodic metal pin array form a first air gap and a second air gap between the upper metal cover plate and the lower metal cover plate respectively; the upper surface and the lower surface of the intermediate metal block enclose a first gap waveguide resonant cavity and a second gap waveguide resonant cavity respectively; the intermediate metal block is hollowed out to form a cross-shaped waveguide resonant cavity; the cross-shaped waveguide resonant cavity is communicated with the first gap waveguide resonant cavity and the second gap waveguide resonant cavity through a cross-shaped coupling hole.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of microwave communication, and particularly discloses a millimeter wave gap waveguide duplexer based on a hybrid cavity structure. BACKGROUND

[0002] In a millimeter wave communication system, such as a 5G / 6G base station and terminal, a point-to-point wireless link, and satellite communication, a duplexer is a key passive device for realizing simultaneous operation of transmitting and receiving signals on a single antenna without interference, and its performance directly affects the communication capacity, sensitivity, and overall size of the system. At present, the mainstream implementation schemes of millimeter wave duplexers include microstrip duplexers and waveguide duplexers. Although microstrip duplexers are easy to integrate and have low cost, their loss increases significantly at millimeter wave frequencies, and their power capacity is limited, and the channel isolation often cannot meet the high standard system requirements. Traditional waveguide duplexers, such as those using branch resonant cavities or diaphragm coupling structures, have the advantages of low loss and high power capacity, but they generally have the problems of large size, complex structure, and high precision requirements for processing and assembly, which result in high cost and are not conducive to system miniaturization. Gap waveguide technology is an emerging solution that forms an artificial magnetic conductor through a periodic array of metal pins, effectively suppressing electromagnetic energy leakage and reducing the dependence on precise mechanical contact. However, existing gap waveguide-based duplexer designs mostly use a structure in which two independent filters are physically connected in parallel and then connected to a common port. This structure is essentially a combination of two filters, resulting in a large lateral size and limited integration. Meanwhile, the main challenge faced by existing technology is how to efficiently excite and separate two independent signal channels in a compact shared physical structure while ensuring high isolation between them. Therefore, there is an urgent need in the field for an innovative duplexer structure that can achieve the synergistic optimization of low loss, high isolation, high integration, and compact size at millimeter wave frequencies. SUMMARY

[0003] The application aims to provide a millimeter wave gap waveguide duplexer based on a hybrid cavity structure, which solves the following technical problems of existing millimeter wave duplexers: (1) the low integration and the problem of being not conducive to system miniaturization caused by the complex structure and large size of traditional waveguide duplexers; (2) the large planar size and limited integration caused by the filter parallel structure of existing gap waveguide duplexers; (3) the difficulty of existing solutions in efficiently exciting and separating two channels and achieving high isolation in a single compact physical structure.

[0004] The technical scheme is that in order to achieve the above-mentioned purpose, the application provides a millimeter wave gap waveguide duplexer based on a hybrid cavity structure, which includes an upper metal cover plate 100, an intermediate metal block 200, and a lower metal cover plate 300 assembled in sequence from top to bottom.

[0005] The upper metal cover plate 100 is provided with a coaxial input port 101; the lower metal cover plate 300 is provided with two coaxial output ports 301 and 302 whose center lines are perpendicular to each other.

[0006] The upper surface of the intermediate metal block 200 is provided with a first periodic metal pin array 201, and the lower surface is provided with a second periodic metal pin array 202; a first air gap is formed between the first periodic metal pin array 201 and the upper metal cover plate 100, and a second air gap is formed between the second periodic metal pin array 202 and the lower metal cover plate 300; the first periodic metal pin array 201 forms a first gap waveguide resonant cavity 11 on the upper surface of the intermediate metal block 200; the second periodic metal pin array 202 forms a second gap waveguide resonant cavity 13 on the lower surface of the intermediate metal block 200;

[0007] The intermediate metal block 200 has a cross-shaped waveguide resonant cavity 12 hollowed out inside; the cross-shaped waveguide resonant cavity 12 is connected to the first gap waveguide resonant cavity 11 and the second gap waveguide resonant cavity 13 through a cross-shaped coupling hole 204 at the top and bottom.

[0008] The coaxial input port 101 is connected to the first gap waveguide resonant cavity 11, and the first coaxial output port 301 and the second coaxial output port 302 are respectively connected to the second gap waveguide resonant cavity 13.

[0009] Furthermore, the coaxial input port 101 is configured to simultaneously excite the TE102 mode and the TE201 mode in the first gap waveguide resonant cavity 11; the first coaxial output port 301 and the second coaxial output port 302 are respectively configured to couple and output the TE102 mode energy and the TE201 mode energy in the second gap waveguide resonant cavity 13, forming two independent signal channels.

[0010] Furthermore, the TE102 mode is coupled to the vertical arm mode excited in the cross-shaped waveguide resonator 12 through the vertical arm of the cross-shaped coupling hole 204; the TE201 mode is coupled to the horizontal arm mode excited in the cross-shaped waveguide resonator 12 through the horizontal arm of the cross-shaped coupling hole 204, and the energy is coupled to the second gap waveguide resonator 13, which excites the TE102 and TE201 modes again respectively.

[0011] Furthermore, the TE102 mode of the first gap waveguide resonator 11, the vertical arm mode of the cross-shaped waveguide resonator 12, and the TE102 mode of the second gap waveguide resonator 13 are sequentially coupled to form a first third-order filtering channel; the TE201 mode of the first gap waveguide resonator 11, the horizontal arm mode of the cross-shaped waveguide resonator 12, and the TE201 mode of the second gap waveguide resonator 13 are sequentially coupled to form a second third-order filtering channel.

[0012] Furthermore, disturbance pins 203 are provided in the first gap waveguide resonant cavity 11 and the second gap waveguide resonant cavity 13.

[0013] Furthermore, the disturbance pin 203 is located at the position where the electric field strength of the TE201 mode is the largest and the electric field strength of the TE102 mode is the smallest in the corresponding first gap waveguide resonant cavity 11 and second gap waveguide resonant cavity 13.

[0014] Beneficial effects: Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects:

[0015] (1) By adopting a hybrid cavity vertical stacking structure of “gap waveguide-cross waveguide-gap waveguide”, and using cross waveguide and cross coupling hole to process the signals of two channels at the same time, the physical integration of duplexer function is realized, the planar size is significantly reduced, and the structure is very compact.

[0016] (2) By utilizing the inherent orthogonality of the TE102 and TE201 modes within the cavity, and combining this with the orthogonal mode separation of the cross-shaped waveguide resonant cavity, the electromagnetic isolation of the two signal channels is physically guaranteed, achieving excellent inter-channel isolation performance. Inheriting the low-loss characteristics of gap waveguides and metallic waveguides, each channel has a third-order filtering response, ensuring excellent filtering performance with low insertion loss within the passband and high selectivity outside the passband.

[0017] (3) By introducing perturbation pins, the channel frequencies related to the TE201 mode can be finely adjusted independently, realizing flexible control of the frequency ratio of the two channels, enhancing the design flexibility and adaptability to manufacturing tolerances. The gap waveguide structure reduces the requirements for precision mechanical contact, and the overall three-layer structure is easy to process and assemble, making it suitable for implementation in the millimeter-wave band. Attached Figure Description

[0018] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, so as to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art. The advantages and implementation methods of the present invention will become more apparent. The content of the accompanying drawings is only used to illustrate and explain the present invention, but does not constitute any limitation on the present invention. In the accompanying drawings:

[0019] Figure 1 This is a structural diagram of the present invention;

[0020] Figure 2 Detailed image of the central metal block;

[0021] Figure 3 These are top and bottom views of the present invention;

[0022] Figure 4 This is a side view of the present invention;

[0023] Figure 5 S-parameter diagram of a duplexer. Detailed Implementation

[0024] The embodiments of the present invention will now be described with reference to the accompanying drawings. The embodiments shown in the drawings are merely exemplary and intended to explain the principles of the present invention, and are not intended to limit the scope of the present invention.

[0025] like Figure 1 As shown, the present invention proposes a millimeter-wave gap waveguide duplexer based on a hybrid cavity structure, including an upper metal cover plate 100, a middle metal block 200 and a lower metal cover plate 300. The upper metal cover plate 100 is provided with a coaxial input port 101; the lower metal cover plate 300 is provided with two first coaxial output ports 301 and second coaxial output ports 302 whose center lines are perpendicular to each other.

[0026] The upper and lower surfaces of the intermediate metal block 200 are respectively provided with a first periodic metal pin array 201 and a second periodic metal pin array 202, which form air gaps with the upper metal cover plate 100 and the lower metal cover plate 300, constituting an artificial magnetic conductor. The first periodic metal pin array 201 forms a first gap waveguide resonant cavity 11 on the upper surface of the intermediate metal block 200, and the second periodic metal pin array 202 forms a second gap waveguide resonant cavity 13 on the lower surface of the intermediate metal block 200. The interior of the intermediate metal block 200 is hollowed out to form a cross-shaped waveguide resonant cavity 12, which is connected to the first gap waveguide resonant cavity 11 and the second gap waveguide resonant cavity 13 through two cross-shaped coupling holes 204 etched on the intermediate metal block.

[0027] The coaxial input port 101 simultaneously excites the TE102 and TE201 modes in the first gap waveguide resonator 11; the TE102 mode is coupled to the vertical arm mode excited in the cross-shaped waveguide resonator 12 through the vertical arm of the cross-shaped coupling hole 204; the TE201 mode is coupled to the horizontal arm mode excited in the cross-shaped waveguide resonator 12 through the horizontal arm of the cross-shaped coupling hole 206, and the energy is then coupled to the second gap waveguide resonator 13, which excites the TE102 and TE201 modes again.

[0028] The TE102 mode energy in the second gap waveguide resonant cavity 13 is extracted by the first coaxial output port 301 to form the center frequency of channel 1. f 1; Energy in TE201 mode is extracted from the second coaxial output port 302 to form the center frequency of channel 2. f 2. Due to the orthogonality of the TE102 and TE201 modes, the two channels naturally have a high degree of isolation.

[0029] To further optimize performance, perturbation pins 203 are provided in the first gap waveguide resonant cavity 11 and the second gap waveguide resonant cavity 13. By adjusting their positions, the resonant frequency of the TE201 mode in the upper cavity can be changed, thereby fine-tuning the center frequency of channel 2. f 2. Achieve frequency ratio f 2 / f 1. Control.

[0030] The achieved duplexer effect is as follows: Figure 5 As shown, the center frequencies of the two channels of this duplexer are 25.43 GHz and 26.92 GHz, respectively. The 3 dB absolute bandwidths are 25.07 GHz to 25.75 GHz (relative bandwidth 2.7%) and 26.62 GHz to 27.26 GHz (relative bandwidth 2.4%), respectively. The insertion losses are 0.53 dB and 0.27 dB, respectively, and the return loss is better than 15 dB for both. Furthermore, the isolation is better than 15 dB in the 23 GHz to 30 GHz frequency range and better than 22 dB in both operating frequency bands.

[0031] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, chip, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, chip, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, chip, article, or apparatus that includes said element. The above descriptions are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A millimeter-wave gap waveguide duplexer based on a hybrid cavity structure, characterized in that, The duplexer includes an upper metal cover plate (100), a middle metal block (200) and a lower metal cover plate (300) assembled from top to bottom. The upper metal cover plate (100) is provided with a coaxial input port (101); the lower metal cover plate (300) is provided with a first coaxial output port (301) and a second coaxial output port (302) whose center lines are perpendicular to each other. The upper surface of the intermediate metal block (200) is provided with a first periodic metal pin array (201), and the lower surface is provided with a second periodic metal pin array (202); a first air gap is formed between the first periodic metal pin array (201) and the upper metal cover plate (100), and a second air gap is formed between the second periodic metal pin array (202) and the lower metal cover plate (300); the first periodic metal pin array (201) forms a first gap waveguide resonant cavity (11) on the upper surface of the intermediate metal block (200); the second periodic metal pin array (202) forms a second gap waveguide resonant cavity (13) on the lower surface of the intermediate metal block (200); the two center lines are perpendicular to each other, meaning that the lines connecting the center of the first coaxial output port (301) and the center of the second coaxial output port (302) and the center of the second gap waveguide resonant cavity (13) are perpendicular to each other; The intermediate metal block (200) has a cross-shaped waveguide resonant cavity (12) hollowed out inside; the cross-shaped waveguide resonant cavity (12) is connected to the first gap waveguide resonant cavity (11) and the second gap waveguide resonant cavity (13) through a cross-shaped coupling hole (204) at the top and bottom; the coaxial input port (101) is connected to the first gap waveguide resonant cavity (11), and the first coaxial output port (301) and the second coaxial output port (302) are connected to the second gap waveguide resonant cavity (13) respectively.

2. The millimeter-wave gap waveguide duplexer based on a hybrid cavity structure according to claim 1, characterized in that, The coaxial input port (101) is configured to simultaneously excite the TE102 mode and the TE201 mode in the first gap waveguide resonant cavity (11); the first coaxial output port (301) and the second coaxial output port (302) are respectively configured to couple and output the TE102 mode energy and the TE201 mode energy in the second gap waveguide resonant cavity (13), forming two independent signal channels.

3. A millimeter-wave gap waveguide duplexer based on a hybrid cavity structure according to claim 2, characterized in that, The TE102 mode is coupled to the vertical arm mode excited in the cross-shaped waveguide resonator (12) through the vertical arm of the cross-shaped coupling hole (204); the TE201 mode is coupled to the horizontal arm mode excited in the cross-shaped waveguide resonator (12) through the horizontal arm of the cross-shaped coupling hole (204), and the energy is coupled to the second gap waveguide resonator (13), which excites the TE102 and TE201 modes again respectively.

4. A millimeter-wave gap waveguide duplexer based on a hybrid cavity structure according to claim 2 or 3, characterized in that, The TE102 mode of the first gap waveguide resonator (11), the vertical arm mode of the cross-shaped waveguide resonator (12), and the TE102 mode of the second gap waveguide resonator (13) are sequentially coupled to form a first third-order filtering channel; the TE201 mode of the first gap waveguide resonator (11), the horizontal arm mode of the cross-shaped waveguide resonator (12), and the TE201 mode of the second gap waveguide resonator (13) are sequentially coupled to form a second third-order filtering channel.

5. A millimeter-wave gap waveguide duplexer based on a hybrid cavity structure according to claim 1 or 2, characterized in that, Disturbance pins (203) are provided in the first gap waveguide resonant cavity (11) and the second gap waveguide resonant cavity (13).

6. A millimeter-wave gap waveguide duplexer based on a hybrid cavity structure according to claim 5, characterized in that, The disturbance pin (203) is located at the position where the electric field strength of the TE201 mode is the largest and the electric field strength of the TE102 mode is the smallest in the corresponding first gap waveguide resonator (11) and second gap waveguide resonator (13).

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