A C-band tuneless duplexer

Abstract

The application discloses a C-band tuning-free duplexer and belongs to the technical field of microwave filters. The tuning-free duplexer comprises an upper conductor and a lower conductor, and the upper conductor and the lower conductor are buckled one above the other to form a waveguide cavity. The upper conductor is provided with a combining port in the middle of the top, and the lower conductor is provided with a low-frequency input / output port and a high-frequency input / output port at the bottom. The waveguide cavity from the low-frequency input / output port to the combining port constitutes a low-end filter, and the waveguide cavity from the high-frequency input / output port to the combining port constitutes a high-end filter. The main bodies of the high-end filter and the low-end filter are both a plurality of waveguide resonant cavities arranged along a straight line, the middle positions of each waveguide resonant cavity are provided with cavity loading, and adjacent waveguide resonant cavities are connected through inter-cavity coupling. The tuning-free duplexer adopts a symmetrical structure and a center loading mode, realizes tuning-free assembly, has the characteristics of high power bearing capacity, low transmission loss and excellent signal isolation, and is suitable for a C-band communication system.

Description

Technical Field

[0001] This invention relates to a C-band tuned-free duplexer, belonging to the field of microwave filter technology. Background Technology

[0002] With the continuous development and widespread application of modern communication technologies, communication systems have placed more stringent technical requirements on duplexers in terms of signal isolation performance and high power carrying capacity. Meanwhile, waveguide duplexers, due to their excellent high-frequency characteristics, are increasingly used in communication equipment, leading to a significant increase in market demand. However, traditional duplexers typically require complex debugging procedures during assembly. This step not only increases production costs but also affects the overall project execution efficiency and schedule to some extent, becoming one of the key factors restricting the speed of system integration and deployment.

[0003] In the prior art, Chinese invention patent CN202411783067.7 discloses "an interdigitated type tune-free superconducting filter," which uses an interdigitated resonator connected to a capacitor coupling structure via a solder plate, and then connected to other resonators to achieve tune-free functionality. However, this solution produces a filter with relatively low power, and requires photolithography or dry etching onto the superconducting mode, making fabrication difficult. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings and defects of existing technologies and provide a C-band tuned-free duplexer. This duplexer achieves tuned-free operation, effectively simplifying the assembly and debugging process, while possessing excellent high-power carrying capacity and high signal suppression performance. Through optimized and innovative structural design, its manufacturing feasibility and production efficiency are further improved, thereby better meeting the urgent needs of modern communication systems for high-performance, high-reliability duplexers in practical engineering applications.

[0005] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows: A C-band tuned-free duplexer includes an upper conductor 1 and a lower conductor 2, wherein the upper conductor 1 and the lower conductor 2 are interlocked to form a waveguide cavity; A combining port 9 is provided at the top center of the upper conductor, and a low-frequency input / output port 16-1 and a high-frequency input / output port 16-2 are provided on both sides of the bottom of the lower conductor, respectively; the waveguide cavity from the low-frequency input / output port 16-1 to the combining port 9 forms a low-end filter, and the waveguide cavity from the high-frequency input / output port 16-2 to the combining port 9 forms a high-end filter. Both the high-end and low-end filters consist of multiple waveguide resonant cavities arranged in a straight line; each waveguide resonant cavity has a cavity loading at its center, and adjacent waveguide resonant cavities are connected through inter-cavity coupling. In the low-end filter, the cavity loading height is higher than that in the high-end filter.

[0006] Furthermore, the upper conductor 1 and the lower conductor 2 are connected by fastening screws 3.

[0007] Furthermore, heat dissipation teeth 10 are provided at the top of the upper conductor and the bottom of the lower conductor.

[0008] Furthermore, the waveguide resonant cavity directly opposite the low-frequency input / output port 16-1 of the low-end filter is a low-frequency transition waveguide cavity 8-1. One side of the cavity is connected to the adjacent waveguide resonant cavity through the low-frequency input / output coupling 7-1, and the other side has a stepped structure A.

[0009] Furthermore, the waveguide resonant cavity directly opposite the high-frequency input / output port 16-2 of the high-end filter is a high-frequency transition waveguide cavity 8-2. One side of the cavity is connected to the adjacent waveguide resonant cavity through the high-frequency input / output coupling 7-2, and the other side has a stepped structure B.

[0010] Furthermore, the top of the lower conductor has a boss located inside the combining port 9 and directly opposite the combining port; the two sides of the boss are the waveguide resonant cavity of the high-end filter and the waveguide resonant cavity of the low-end filter, and these two waveguide resonant cavities are transitioned to the combining port through the boss.

[0011] Furthermore, both the upper and lower conductors are provided with guide grooves at their edges, and the guide grooves are directly opposite each other.

[0012] Furthermore, the cavity couplings are all rectangular coupling window structures, and the waveguide resonant cavities and inter-cavity couplings are arranged in a straight line.

[0013] Furthermore, both the high-end and low-end filters have eight waveguide resonant cavities and eight cavity loadings.

[0014] The technical advancements achieved by this invention due to the adoption of the above technical solutions are as follows: 1. This invention employs a square waveguide cavity as the basic resonant structure and integrates a capacitor loading element within the cavity. This loading method effectively reduces the overall size of the duplexer. Simultaneously, this capacitor loading technology achieves miniaturization while maintaining a high power handling capacity for the filter, ensuring a power capacity of no less than 2000W under C-band operating conditions, thus meeting the needs of high-power applications.

[0015] 2. This invention employs a symmetrical cuboid loading structure, with the loading element positioned at the geometric center of the waveguide cavity. This loading method provides excellent structural symmetry, enabling the duplexer to maintain superior performance even with unavoidable manufacturing tolerances under current machining conditions, thus achieving the goal of tune-free design. This design significantly reduces the workload during later assembly and debugging stages, saving considerable debugging time. Furthermore, since there is no need to insert tuning screws during debugging, it effectively avoids potential tip discharge caused by screws protruding into the resonant cavity, thereby ensuring the performance stability and reliability of the duplexer under high-power operation. In addition, this loading method enhances the duplexer's ability to suppress second harmonics, contributing to improved signal transmission quality and filtering performance of the overall system.

[0016] 3. This invention significantly enhances the signal isolation capability between the transmit and receive channels of the duplexer by employing a multi-stage resonant cavity cascaded structure, thereby effectively improving its overall isolation. This design not only optimizes the duplexer's performance in complex electromagnetic environments but also further ensures the stability and reliability of the system during high-frequency operation.

[0017] 4. This invention employs a symmetrical filter structure, in which the waveguide resonant cavity and the rectangular coupling window are arranged sequentially along a straight line, forming a simple and easily implemented duplexer design. This structure offers significant advantages during manufacturing: the duplexer can be divided into two independent parts—an upper conductor and a lower conductor—along a central plane, each requiring separate machining. This modular manufacturing approach not only reduces manufacturing difficulty but also significantly improves production efficiency, facilitating mass production and quality control. Attached Figure Description

[0018] Figure 1 This is a schematic diagram (front view) of the present invention. Figure 2 This is a schematic diagram (top view) of the structure of the present invention. Figure 3 This is a schematic diagram (bottom view) of the structure of the present invention; Figure 4 This is a schematic diagram of the upper conductor structure of the present invention; Figure 5 This is a schematic diagram of the lower conductor structure of the present invention; Figure 6 This is a cross-sectional view of the structure according to an embodiment of the present invention.

[0019] The duplexer includes an upper conductor 1, a lower conductor 2, and a fastening screw 3. The upper conductor 1 includes a low-frequency waveguide resonant cavity 4-1, a high-frequency waveguide resonant cavity 4-2, a low-frequency inter-cavity coupling 5-1, a high-frequency inter-cavity coupling 5-2, a low-frequency cavity loading 6-1, a high-frequency cavity loading 6-2, a low-frequency input / output coupling 7-1, a low-frequency input / output coupling 7-2, a low-frequency transition waveguide cavity 8-1, a high-frequency transition waveguide cavity 8-2, a combining port 9, and a heat dissipation tooth 10. The lower conductor 2 includes a low-frequency waveguide resonant cavity 11-1, a high-frequency waveguide resonant cavity 11-2, a low-frequency inter-cavity coupling 12-1, a high-frequency inter-cavity coupling 12-2, a low-frequency cavity loading 13-1, a high-frequency cavity loading 13-2, a low-frequency input-output coupling 14-1, a low-frequency input-output coupling 14-2, a low-frequency transition waveguide cavity 15-1, a high-frequency transition waveguide cavity 15-2, a low-frequency input-output port 16-1, a high-frequency input-output port 16-2, a combining loading structure 17, heat dissipation teeth 18, and a flow guide groove 19. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. These embodiments are intended to aid in understanding the technical solutions of the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0021] like Figures 1 to 5 As shown, this embodiment provides a C-band tuned-free duplexer, mainly comprising an upper conductor 1, a lower conductor 2, and several fastening screws 3. The upper conductor 1 and the lower conductor 2 are interlocked and fixedly connected by the fastening screws 3, forming a closed waveguide cavity structure. The upper conductor 1 and the lower conductor 2 adopt a symmetrical structural design, that is, the entire duplexer body is divided into two parts along the middle split plane, forming two symmetrical parts, which facilitates processing, manufacturing, and assembly.

[0022] A combining port 9 is located at the top center of the upper conductor 1. This combining port 9 uses a standard FDP58 flange structure and is used to connect to an external antenna or combining unit. The bottom sides of the lower conductor 2 have low-frequency input / output ports 16-1 and high-frequency input / output ports 16-2, respectively, for receiving low-frequency and high-frequency signals. The waveguide cavity between the low-frequency input / output port 16-1 and the combining port 9 forms the low-end filter channel, and the waveguide cavity between the high-frequency input / output port 16-2 and the combining port 9 forms the high-end filter channel.

[0023] The left side of the upper conductor 1 constitutes the upper half of the low-end filter, and the right side constitutes the upper half of the high-end filter.

[0024] The low-end filter section includes eight waveguide resonant cavities 4-1 arranged sequentially along a straight line. Each waveguide resonant cavity 4-1 has a cavity loading 6-1 at its geometric center for capacitive loading and frequency adjustment. Adjacent waveguide resonant cavities 4-1 are connected via inter-cavity coupling 5-1, which is a rectangular coupling window structure used to control the inter-cavity energy coupling strength. The input side of the low-end filter includes a low-frequency transition waveguide cavity 8-1. One side of this cavity is connected to the adjacent waveguide resonant cavity 4-1 via a low-frequency input / output coupling 7-1, while the other side has a stepped structure A for impedance matching with the low-frequency input / output port 16-1.

[0025] The high-end filter section includes eight waveguide resonant cavities 4-2 arranged sequentially along a straight line. Each waveguide resonant cavity 4-2 has a cavity loading 6-2 located at its geometric center. Adjacent waveguide resonant cavities 4-2 are connected via inter-cavity couplings 5-2, which are also rectangular coupling window structures. The input side of the high-end filter includes a high-frequency transition waveguide cavity 8-2. One side of this cavity is connected to the adjacent waveguide resonant cavity 4-2 via a high-frequency input / output coupling 7-2, while the other side has a stepped structure B for impedance matching with the high-frequency input / output port 16-2.

[0026] The top of the upper conductor 1 is also provided with multiple heat dissipation teeth 10 to improve heat dissipation under high power operating conditions.

[0027] The left side of the lower conductor 2 constitutes the lower half of the low-end filter, and the right side constitutes the lower half of the high-end filter. Their structures are symmetrically distributed vertically with the corresponding parts in the upper conductor 1.

[0028] Specifically, the low-end filter section of the lower conductor 2 includes eight waveguide resonant cavities 11-1, eight cavity loading 13-1, eight inter-cavity couplings 12-1, a low-frequency transition waveguide cavity 15-1, and a low-frequency input-output coupling 14-1, which correspond one-to-one with the waveguide resonant cavity 4-1, cavity loading 6-1, inter-cavity coupling 5-1, low-frequency transition waveguide cavity 8-1, and low-frequency input-output coupling 7-1 in the upper conductor 1, and are arranged symmetrically above and below with the contact surface as the reference.

[0029] The high-end filter section of the lower conductor 2 includes eight waveguide resonant cavities 11-2, eight cavity loading 13-2, eight inter-cavity couplings 12-2, one high-frequency transition waveguide cavity 15-2, and a high-frequency input-output coupling 14-2, which correspond one-to-one with the waveguide resonant cavity 4-2, cavity loading 6-2, inter-cavity coupling 5-2, high-frequency transition waveguide cavity 8-2, and high-frequency input-output coupling 7-2 in the upper conductor 1, and are arranged symmetrically above and below with the contact surface as the reference.

[0030] The bottom of the lower conductor 2 is also provided with multiple heat dissipation teeth 18 to enhance the overall heat dissipation performance.

[0031] At the position corresponding to the combining port 9, a boss structure (i.e., combining loading structure 17) is provided on the top of the lower conductor 2. The boss is located inside the combining port 9 and directly opposite the combining port 9. The two sides of the boss are adjacent to the last waveguide resonator of the low-end filter and the last waveguide resonator of the high-end filter, respectively, forming a T-shaped waveguide combining structure, so that the low-frequency signal and the high-frequency signal can be combined and output at the combining port 9, or vice versa to separate the signals.

[0032] The upper conductor 1 and the lower conductor 2 are respectively provided with guide grooves 19 at corresponding positions on their edges, and they are aligned during assembly. During the assembly process, the guide grooves 19 are filled with solder, and then the upper conductor 1 and the lower conductor 2 are fixed by fastening screws 3, and then the whole assembly is welded, thereby effectively improving the waterproof performance and environmental adaptability of the duplexer.

[0033] In this embodiment, both the low-end and high-end filters employ a multi-stage waveguide resonant cavity cascade structure, and the resonant frequency is precisely set through cavity loading. The heights of cavity loads 6-1 and 13-1 in the low-end filter are higher than the heights of cavity loads 6-2 and 13-2 in the high-end filter to accommodate the resonance requirements of different frequency bands. Because the entire structure adopts a symmetrical design and the loading elements are located at the geometric center of the waveguide cavity, performance indicators can be met without subsequent tuning within conventional machining tolerances, achieving a tuning-free function.

[0034] Under high-power operating conditions, the duplexer, through the combined effect of waveguide resonant cavity structure, symmetrical loading design and heat dissipation teeth, has a power carrying capacity of no less than 2000W, while achieving low transmission loss, excellent signal isolation performance and effective suppression of second harmonics, meeting the application requirements of C-band communication systems for high-performance duplexers.

Claims

1. A C-band tuned-free duplexer, characterized in that, It includes an upper conductor (1) and a lower conductor (2), wherein the upper conductor (1) and the lower conductor (2) are interlocked to form a waveguide cavity; A combining port (9) is provided at the top center of the upper conductor, and a low-frequency input / output port (16-1) and a high-frequency input / output port (16-2) are provided on both sides of the bottom of the lower conductor, respectively; the waveguide cavity from the low-frequency input / output port (16-1) to the combining port (9) forms a low-end filter, and the waveguide cavity from the high-frequency input / output port (16-2) to the combining port (9) forms a high-end filter; Both the high-end and low-end filters consist of multiple waveguide resonant cavities arranged in a straight line; each waveguide resonant cavity has a cavity loading at its center, and adjacent waveguide resonant cavities are connected through inter-cavity coupling. In the low-end filter, the cavity loading height is higher than that in the high-end filter.

2. The C-band tuned-free duplexer according to claim 1, characterized in that, The upper conductor (1) and the lower conductor (2) are connected by fastening screws (3).

3. A C-band tuned-free duplexer according to claim 1, characterized in that, The top of the upper conductor and the bottom of the lower conductor are both provided with heat dissipation teeth (10).

4. A C-band tuned-free duplexer according to claim 1, characterized in that, The low-frequency input / output port (16-1) of the low-end filter is directly opposite the waveguide resonant cavity, which is a low-frequency transition waveguide cavity (8-1). One side of the cavity is connected to the adjacent waveguide resonant cavity through the low-frequency input / output coupling (7-1), and the other side has a stepped structure A.

5. A C-band tuned-free duplexer according to claim 1, characterized in that, The high-frequency input / output port (16-2) of the high-end filter is directly opposite the waveguide resonant cavity, which is a high-frequency transition waveguide cavity (8-2). One side of the cavity is connected to the adjacent waveguide resonant cavity through the high-frequency input / output coupling (7-2), and the other side has a stepped structure B.

6. A C-band tuned-free duplexer according to claim 1, characterized in that, The top of the lower conductor has a boss located inside the combining port (9) and directly opposite the combining port; the two sides of the boss are the waveguide resonant cavity of the high-end filter and the waveguide resonant cavity of the low-end filter, and the two waveguide resonant cavities are connected to the combining port through the boss.

7. A C-band tuned-free duplexer according to claim 1, characterized in that, Both the upper and lower conductors have flow guide grooves on their edges, and the flow guide grooves are directly opposite each other.

8. A C-band tuned-free duplexer according to claim 1, characterized in that, The cavity couplings are all rectangular coupling window structures, and the waveguide resonant cavities and inter-cavity couplings are all arranged in a straight line.

9. A C-band tuned-free duplexer according to claim 1, characterized in that, Both the high-end and low-end filters have eight waveguide resonant cavities and eight cavity loadings.

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