A high-selectivity gap waveguide dual-band bandpass filter for satellite communication

Abstract

This invention discloses a highly selective gapped waveguide dual-passband bandpass filter for satellite communication. The filter includes a gapped waveguide structure. The gapped waveguide structure contains two rows of resonant cavities distributed on opposite sides of a center line. The first row, from left to right, consists of a second resonant cavity, a first resonant cavity, and a fourth resonant cavity. The second row, from left to right, consists of a third resonant cavity, a sixth resonant cavity, and a fifth resonant cavity. Electromagnetic energy coupling is achieved between the first and second resonant cavities, between the second and third resonant cavities, between the third and sixth resonant cavities, between the first and sixth resonant cavities, between the first and fourth resonant cavities, between the fourth and fifth resonant cavities, and between the fifth and sixth resonant cavities through coupling windows. The filter's input port is fed to the first resonant cavity via a coaxial feed probe, and the output port is taken out from the sixth resonant cavity via a coaxial feed probe.

Description

Technical Field

[0001] This invention relates to the field of microwave passive device technology, and in particular to a highly selective gap waveguide dual-passband bandpass filter for satellite communication. Background Technology

[0002] With the development of satellite communication systems towards higher frequencies and multiple frequency bands, the demand for high-performance bandpass filters is becoming increasingly urgent. Traditional microwave filters often face drawbacks in dual-band applications, such as large size, high insertion loss, and insufficient selectivity, making it difficult to meet the core requirements of satellite communication for compactness, low loss, and high-precision filtering. Gap waveguide technology, with its significant advantages of low transmission loss, high integration, and suppression of surface waves, provides an effective path for miniaturized filter design. This invention innovatively achieves high-selectivity dual-passband filtering. By precisely controlling the electromagnetic coupling path, it ensures efficient isolation of dual-band signals, improves the spectrum utilization and anti-interference performance of satellite communication systems, and provides key support for next-generation satellite communication equipment.

[0003] Currently, some publicly available designs of microstrip dual-passband filters based on step impedance resonators employ multi-stage parallel coupled lines, resulting in high insertion loss and significant degradation of high-frequency performance. Furthermore, while ultra-wideband dual-passband response is achieved using hybrid short-circuit and open-circuit stubs, the microstrip circuit area is large, and harmonic suppression capability is limited, making it difficult to meet the compactness and high selectivity requirements of satellite communication. Even with the introduction of transmission zeros through parallel coupled lines to improve inter-passband isolation, the inherent losses of the microstrip process remain, and the problem of insufficient high-frequency harmonic suppression is not resolved, resulting in an overall performance that cannot simultaneously meet the requirements of low loss and high selectivity.

[0004] In summary, the problem with existing technologies is that traditional dual-passband filters cannot simultaneously achieve simplicity of structure, high selectivity, miniaturization, and ease of design. They often rely on complex coupling topologies, multimode resonators, or additional isolation structures, leading to increased size, higher losses, or increased implementation difficulty, making it difficult to meet the comprehensive requirements of modern high-frequency wireless communication systems for high performance, compact integration, and engineering feasibility. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing dual-passband filters by providing a highly selective gapped waveguide dual-passband filter for satellite communication. By innovatively utilizing gapped waveguide technology to construct parallel coupled electromagnetic paths, high-precision isolation and low-loss transmission of dual-band signals are achieved, providing a compact, high-performance, and highly reliable core filtering solution for satellite communication systems.

[0006] Technical solution: In order to achieve the above objectives, the present invention proposes a high-selectivity gap waveguide dual-passband bandpass filter for satellite communication. The filter includes a gap waveguide structure (1) and a first resonant cavity (2), a second resonant cavity (3), a third resonant cavity (4), a fourth resonant cavity (5), a fifth resonant cavity (6) and a sixth resonant cavity (7) located within the gap waveguide structure (1).

[0007] The first resonant cavity (2) is located in the middle of the first row below the center line of the gap waveguide structure (1);

[0008] The second resonant cavity (3) is located on the left side of the first row below the center line of the gap waveguide structure (1);

[0009] The fourth resonant cavity (5) is located on the right side of the first row below the center line of the gap waveguide structure (1);

[0010] The third resonant cavity (4) is located on the left side of the second row above the center line of the gap waveguide structure (1);

[0011] The fifth resonant cavity (6) is located on the right side of the second row above the center line of the gap waveguide structure (1);

[0012] The sixth resonant cavity (7) is located in the middle of the second row on the side of the center line of the gap waveguide structure (1);

[0013] The gap waveguide structure (1) has an input port (8) in the middle of the first row, with its inner conductor extending into the first resonant cavity (2); and an output port (9) in the middle of the second row, with its inner conductor extending into the sixth resonant cavity (7).

[0014] Electromagnetic energy coupling is achieved between the first resonant cavity (2) and the second resonant cavity (3) through a coupling window (10), between the second resonant cavity (3) and the third resonant cavity (4) through a coupling window (11), between the third resonant cavity (4) and the sixth resonant cavity (7) through a coupling window (12), between the first resonant cavity (2) and the fourth resonant cavity (5) through a coupling window (13), between the fourth resonant cavity (5) and the fifth resonant cavity (6) through a coupling window (14), between the fifth resonant cavity (6) and the sixth resonant cavity (7) through a coupling window (15), and between the first resonant cavity (2) and the sixth resonant cavity (7) through a coupling window (16).

[0015] Furthermore, the heights of the first resonant cavity (2), the second resonant cavity (3), the third resonant cavity (4), the fourth resonant cavity (5), the fifth resonant cavity (6), and the sixth resonant cavity (7) are all equal, wherein the lengths of the first resonant cavity (2) and the sixth resonant cavity (7), the second resonant cavity (3) and the third resonant cavity (4), and the fourth resonant cavity (5) and the fifth resonant cavity (6) are the same.

[0016] Furthermore, the coupling windows (10) and (12), and coupling windows (13) and (15) are the same size.

[0017] Furthermore, the input port (8) and the output port (9) are symmetrical structures and have the same size.

[0018] Furthermore, both the input port (8) and the output port (9) adopt coaxial interfaces.

[0019] Beneficial effects: Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects:

[0020] (1) The structure is simple, requiring no additional structure or space, which facilitates processing and integration and significantly reduces production costs;

[0021] (2) Easy to design, adopts parallel coupled path structure, realizes modular design, and greatly reduces design and debugging complexity;

[0022] (3) High selectivity: The three parallel coupling paths generate a total of 4 transmission zeros in the passband and out-of-band, which significantly improves selectivity;

[0023] (4) Compact size, parallel structure effectively reduces filter size, which is superior to traditional cascaded cavity design;

[0024] (5) High power transmission: The metal gap waveguide structure provides higher power capacity to meet the high reliability requirements of satellite communication systems. Attached Figure Description

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, and the advantages of the present invention in the above and / or other aspects will become clearer.

[0026] Figure 1 This is a three-dimensional structural schematic diagram of the high-selectivity gap waveguide dual-passband bandpass filter for satellite communication systems according to the present invention.

[0027] Figure 2 This is the XZ-plane structural diagram of the first, second, third, fourth, fifth, and sixth resonant cavities.

[0028] Figure 3This is a diagram showing the XZ-plane structural parameters of the first, second, third, fourth, fifth, and sixth resonant cavities.

[0029] Figure 4 This is a diagram showing the XY plane structural parameters of the first, second, third, fourth, fifth, and sixth resonant cavities.

[0030] Figure 5 This is a simulation curve of the S-parameters of a high-selectivity gap waveguide dual-passband bandpass filter for satellite communication systems.

[0031] In the diagram of the specification, the gap waveguide structure is 1; the first resonant cavity is 2; the second resonant cavity is 3; the third resonant cavity is 4; the fourth resonant cavity is 5; the fifth resonant cavity is 6; the sixth resonant cavity is 7; the input port is 8; the output port is 9; the coupling window is 10 between the first resonant cavity 2 and the second resonant cavity 3; the coupling window is 11 between the second resonant cavity 3 and the third resonant cavity 4; the coupling window is 12 between the third resonant cavity 4 and the sixth resonant cavity 7; the coupling window is 13 between the first resonant cavity 2 and the fourth resonant cavity 5; the coupling window is 14 between the fourth resonant cavity 5 and the fifth resonant cavity 6; the coupling window is 15 between the fifth resonant cavity 6 and the sixth resonant cavity 7; and the coupling window is 16 between the first resonant cavity 2 and the sixth resonant cavity 7. Detailed Implementation

[0032] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0033] like Figures 1 to 2 As shown, the high-selectivity gap waveguide dual-passband bandpass filter for satellite communication includes a gap waveguide structure 1, and a first resonant cavity 2, a second resonant cavity 3, a third resonant cavity 4, a fourth resonant cavity 5, a fifth resonant cavity 6, and a sixth resonant cavity 7 located within the gap waveguide structure 1.

[0034] Among them, the first resonant cavity 2 is located in the middle of the first row below the center line of the gap waveguide structure 1, the second resonant cavity 3 is located on the left side of the first row below the center line of the gap waveguide structure 1, the third resonant cavity 4 is located on the left side of the second row above the center line of the gap waveguide structure 1, the fourth resonant cavity 5 is located on the right side of the first row below the center line of the gap waveguide structure 1, the fifth resonant cavity 6 is located on the right side of the second row above the center line of the gap waveguide structure 1, and the sixth resonant cavity 7 is located in the middle of the second row above the center line of the gap waveguide structure 1.

[0035] The first row of the gap waveguide structure 1 has an input port 8 at its center, with its inner conductor extending into the first resonant cavity 2; the second row has an output port 9 at its center, with its inner conductor extending into the sixth resonant cavity 7.

[0036] The energy transfer path includes three parallel electromagnetic coupling paths: the first path passes through the first resonant cavity 2, the second resonant cavity 3, the third resonant cavity 4, and the sixth resonant cavity 7 in sequence. The first resonant cavity 2 and the second resonant cavity 3 are coupled through the coupling window 10, the second resonant cavity 3 and the third resonant cavity 4 are coupled through the coupling window 11, and the third resonant cavity 4 and the sixth resonant cavity 7 are coupled through the coupling window 12.

[0037] The second path passes through the first resonant cavity 2 and the sixth resonant cavity 7, with energy coupling between them achieved through coupling window 16. The third path passes through the first resonant cavity 2, the fourth resonant cavity 5, the fifth resonant cavity 6, and the sixth resonant cavity 7 in sequence. Energy coupling between the first resonant cavity 2 and the fourth resonant cavity 5 is achieved through coupling window 13, between the fourth resonant cavity 5 and the fifth resonant cavity 6 through coupling window 14, and between the fifth resonant cavity 6 and the sixth resonant cavity 7 through coupling window 15. These three paths together constitute the parallel coupling network of the dual-passband filter.

[0038] The heights of the first resonant cavity 2, the second resonant cavity 3, the third resonant cavity 4, the fourth resonant cavity 5, the fifth resonant cavity 6, and the sixth resonant cavity 7 are all equal, wherein the lengths of the first resonant cavity 2 and the sixth resonant cavity 7, the second resonant cavity 3 and the third resonant cavity 4, and the fourth resonant cavity 5 and the fifth resonant cavity 6 are the same.

[0039] The coupling windows 10 and 12, and coupling windows 13 and 15 are of the same size.

[0040] like Figures 3 to 4As shown, in this high-selectivity gap waveguide dual-passband bandpass filter for satellite communication, the width a1 of the first resonant cavity 2 is 14.48 mm and the length c1 is 14.15 mm; the width a2 of the second resonant cavity 3 is 18.37 mm and the length c2 is 15.65 mm; the dimensions of the third resonant cavity 4 are the same as those of the second resonant cavity 3, i.e., width a2 = 18.37 mm and length c2 = 15.65 mm; the width a3 of the fourth resonant cavity 5 is 17.45 mm and the length c3 is 15.4 mm; the dimensions of the fifth resonant cavity 6 are the same as those of the fourth resonant cavity 5, i.e., width a3 = 17.45 mm and length c3 = 15.4 mm; the dimensions of the sixth resonant cavity 7 are the same as those of the first resonant cavity 2, i.e., width a1 = 14.48 mm and length c1 = 14.15 mm; and the height h of all resonant cavities is 9.525 mm. The width l1 of the coupling window 10 between the first resonant cavity 2 and the second resonant cavity 3 is 10.37 mm, and the width l1 of the coupling window 12 between the third resonant cavity 4 and the sixth resonant cavity 7 is also l1; the width l2 of the coupling window 13 between the first resonant cavity 2 and the fourth resonant cavity 5 is 10.86 mm, and the width l2 of the coupling window 15 between the fifth resonant cavity 6 and the sixth resonant cavity 7 is also l2; the width l3 of the coupling window 11 between the second resonant cavity 3 and the third resonant cavity 4 is 12.83 mm; the width l4 of the coupling window 16 between the first resonant cavity 2 and the sixth resonant cavity 7 is 6.32 mm; and the width l5 of the coupling window 14 between the fourth resonant cavity 5 and the fifth resonant cavity 6 is 4.37 mm. The height h of the capacitive coupling cylinder in the coupling window between the second resonant cavity 3 and the third resonant cavity 4 is... 23 The height h of the capacitive coupling cylinder in the coupling window between the fourth resonant cavity 5 and the fifth resonant cavity 6 is 4.669 mm. 45 The diameter of the two capacitively coupled cylinders is 3.315 mm; the height h1 of the pin in the gap waveguide structure is 9.375 mm, the gap distance d between adjacent pins is 1.655 mm, and the pin has a square cross-section with a side length of 0.83 mm.

[0041] The input port 8 and output port 9 are symmetrical and identical in size. They are both fed by a coaxial line. The inner conductor extends into the resonant cavity to a depth of 2.72 mm, the inner conductor radius is 0.89598 mm, and the outer conductor radius is 3 mm.

[0042] This example demonstrates a high-selectivity gap waveguide dual-passband bandpass filter for satellite communication systems, modeled and simulated using the electromagnetic simulation software HFSS 2024 R1. Figure 5This is a simulation curve of the S-parameters of the high-selectivity gap waveguide dual-passband bandpass filter for satellite communication systems in this example. As can be seen from the figure, the center frequency of this sixth-order dual-passband filter is 12 GHz, the 3dB bandwidths of the lower passband and upper passband are 456 MHz and 444 MHz, respectively, and there are three resonant poles in each passband. Two transmission zeros are generated outside the passband at 10.644 GHz and 13.2 GHz, and two transmission zeros are generated between the passbands at 11.852 GHz and 12.214 GHz, which makes the filter have excellent frequency selectivity.

[0043] In summary, the high-selectivity gapped waveguide dual-passband bandpass filter of this invention innovatively adopts a modular design architecture, decomposing the sixth-order dual-passband filtering function into three parallel coupled path units. This design eliminates redundant components in traditional cascaded structures, requiring no additional space or complex assembly processes, significantly improving processing and integration efficiency and reducing manufacturing costs. Simultaneously, the compact parallel structure effectively reduces the filter size, perfectly adapting to the stringent space resource constraints of satellite communication equipment. The introduction of metallic gapped waveguide technology not only eliminates the high-loss problem in traditional waveguides but also significantly improves power transmission capacity, ensuring stable high-precision signal output under extreme conditions. This design advantage fully meets the core requirements of satellite communication systems for high reliability, high selectivity, and miniaturized filters.

[0044] This invention provides a concept and method for a highly selective gapped waveguide dual-passband bandpass filter for satellite communication. Many methods and approaches exist for implementing this technical solution; the above description is merely a preferred embodiment of the invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention. All components not explicitly stated in this embodiment can be implemented using existing technologies.

Claims

1. A high-selectivity gapped waveguide dual-passband bandpass filter for satellite communication, characterized in that, It includes a gap waveguide structure (1), and a first resonant cavity (2), a second resonant cavity (3), a third resonant cavity (4), a fourth resonant cavity (5), a fifth resonant cavity (6) and a sixth resonant cavity (7) located within the gap waveguide structure (1); The first resonant cavity (2) is located in the middle of the first row below the center line of the gap waveguide structure (1); The second resonant cavity (3) is located on the left side of the first row below the center line of the gap waveguide structure (1); The fourth resonant cavity (5) is located on the right side of the first row below the center line of the gap waveguide structure (1); The third resonant cavity (4) is located on the left side of the second row above the center line of the gap waveguide structure (1); The fifth resonant cavity (6) is located on the right side of the second row above the center line of the gap waveguide structure (1); The sixth resonant cavity (7) is located in the middle of the second row on the side of the center line of the gap waveguide structure (1); The gap waveguide structure (1) has an input port (8) in the middle of the first row, with its inner conductor extending into the first resonant cavity (2); and an output port (9) in the middle of the second row, with its inner conductor extending into the sixth resonant cavity (7). Electromagnetic energy coupling is achieved between the first resonant cavity (2) and the second resonant cavity (3) through a coupling window (10), between the second resonant cavity (3) and the third resonant cavity (4) through a coupling window (11), between the third resonant cavity (4) and the sixth resonant cavity (7) through a coupling window (12), between the first resonant cavity (2) and the fourth resonant cavity (5) through a coupling window (13), between the fourth resonant cavity (5) and the fifth resonant cavity (6) through a coupling window (14), between the fifth resonant cavity (6) and the sixth resonant cavity (7) through a coupling window (15), and between the first resonant cavity (2) and the sixth resonant cavity (7) through a coupling window (16).

2. The high-selectivity gapped waveguide dual-passband bandpass filter for satellite communication according to claim 1, characterized in that, The heights of the first resonant cavity (2), the second resonant cavity (3), the third resonant cavity (4), the fourth resonant cavity (5), the fifth resonant cavity (6), and the sixth resonant cavity (7) are all equal. The lengths of the first resonant cavity (2) and the sixth resonant cavity (7), the second resonant cavity (3) and the third resonant cavity (4), and the fourth resonant cavity (5) and the fifth resonant cavity (6) are the same.

3. The high-selectivity gapped waveguide dual-passband bandpass filter for satellite communication according to claim 1, characterized in that, The coupling windows (10) and (12), and coupling windows (13) and (15) are the same size.

4. A high-selectivity gapped waveguide dual-passband bandpass filter for satellite communication according to claim 1, characterized in that, The input port (8) and the output port (9) are symmetrical and of the same size.

5. A high-selectivity gapped waveguide dual-passband bandpass filter for satellite communication according to claim 4, characterized in that, Both the input port (8) and the output port (9) use coaxial interfaces.

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