High-isolation multi-coupling-path substrate integrated waveguide filter cross High-isolation multi-coupling-path substrate integrated waveguide filter cross

Abstract

The application discloses a high-isolation substrate integrated waveguide filter cross based on multiple coupling paths, and aims at the problem of poor isolation under an absolute bandwidth of 1.44% or 4.75% in the existing filter cross realized by orthogonal modes. A fifth resonant cavity is arranged in the center of a dielectric substrate, a first resonant cavity, a second resonant cavity, a third resonant cavity and a fourth resonant cavity are arranged around the fifth resonant cavity, the fifth resonant cavity is connected with the first resonant cavity, the second resonant cavity, the third resonant cavity and the fourth resonant cavity, a 180-degree phase difference is generated through two slot openings, and the high-isolation filter cross is realized. Compared with the traditional orthogonal mode realization mode, the isolation is improved by 9dB under the same bandwidth.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of microwave filters, and particularly relates to a high-isolation substrate integrated waveguide filtering crossover based on multiple coupling paths. BACKGROUND

[0002] Compared with a rectangular waveguide, a substrate integrated waveguide has the advantages of small size, easy integration with a planar circuit and the like. In the design of microwave and millimeter wave integrated circuits, the demand for high integration and easy assembly is increasingly urgent.

[0003] In recent years, filtering crossovers have attracted much attention in many communication systems. The filtering crossover not only enables two signals to be cross-transmitted and maintain high isolation, but also is usually present in an array antenna beam forming network to realize a microwave device with frequency selection characteristics.

[0004] Existing substrate integrated waveguide filtering crossovers, such as a filtering crossover (Novel Substrate Integrated Waveguide Filtering Crossover Using Orthogonal Degenerate Modes) published in IEEE Microwave and Wireless Component Letters Volume 27, have five resonant cavities that are TE 102 and TE 201 modes, and the filtering crossover characteristics are realized by orthogonal modes. The structure has a large size, and the isolation is greater than 30 dB at an absolute bandwidth of 1.44%.

[0005] For example, a filtering crossover (Miniaturized Substrate Integrated Waveguide Filtering Crossover) published in EDAPS 2017 has common resonant cavities that are TE 102 and TE 201 modes, and four resonant cavities around the four common resonant cavities are TE 101 modes. Although the structure size is relatively small compared with the above filtering crossover, the filtering crossover characteristics are still realized by orthogonal modes, and the isolation is greater than 20 dB at an absolute bandwidth of 4.75%. SUMMARY

[0006] The application aims to provide a high-isolation substrate integrated waveguide filtering crossover based on multiple coupling paths, which has a compact structure, high space utilization, and an isolation that can be improved by 9 dB at the same bandwidth compared with a conventional orthogonal mode implementation.

[0007] To solve the above problems, the technical scheme of the application is as follows:

[0008] A high-isolation substrate integrated waveguide filter cross based on multiple coupling paths, comprising: a first metal layer, a second metal layer and a dielectric substrate arranged between the first metal layer and the second metal layer;

[0009] Wherein, the first input port, the first output port, the second input port and the second output port are arranged on the first metal layer;

[0010] The fifth resonant cavity is arranged in the center of the dielectric substrate, and the first resonant cavity, the second resonant cavity, the third resonant cavity and the fourth resonant cavity are arranged around the fifth resonant cavity;

[0011] The first input port excites the first resonant cavity, and the third resonant cavity is coupled to the first output port for output;

[0012] The second input port excites the second resonant cavity, and the fourth resonant cavity is coupled to the second output port for output;

[0013] The fifth resonant cavity and the first resonant cavity, the second resonant cavity, the third resonant cavity and the fourth resonant cavity are connected through two slot openings to realize multiple coupling paths.

[0014] According to an embodiment of the present application, the fifth resonant cavity and the first resonant cavity, the second resonant cavity, the third resonant cavity and the fourth resonant cavity generate a 180° phase difference through two slot openings to realize a high-isolation filter cross.

[0015] According to an embodiment of the present application, the first resonant cavity, the second resonant cavity, the third resonant cavity and the fourth resonant cavity generate TE 101 mode, and the fifth resonant cavity generates TE 102 mode or TE 201 mode.

[0016] According to an embodiment of the present application, the first resonant cavity, the second resonant cavity, the third resonant cavity, the fourth resonant cavity and the fifth resonant cavity are square-shaped;

[0017] The length-width ratio of the first resonant cavity, the second resonant cavity, the third resonant cavity and the fourth resonant cavity is 1:2;

[0018] The length-width ratio of the fifth resonant cavity is 1:1.

[0019] According to an embodiment of the present application, two slot openings are arranged on each side of the fifth resonant cavity, and the two slot openings on each side are located at one-fourth of the length and three-fourths of the length, respectively.

[0020] According to an embodiment of the present application, a plurality of metalized via holes are arranged on the dielectric substrate to form the first resonant cavity, the second resonant cavity, the third resonant cavity, the fourth resonant cavity and the fifth resonant cavity.

[0021] Compared with the prior art, the present application has the following advantages and positive effects:

[0022] 1) The high-isolation multi-coupling-path substrate integrated waveguide filter crosser according to an embodiment of the present application is used to solve the problem of poor isolation at an absolute bandwidth of 1.44% or 4.75% in the prior art filter crosser realized by using orthogonal modes. The fifth resonant cavity is arranged at the center of the dielectric substrate, and the first resonant cavity, the second resonant cavity, the third resonant cavity and the fourth resonant cavity are arranged around the fifth resonant cavity. The fifth resonant cavity and the first resonant cavity, the second resonant cavity, the third resonant cavity and the fourth resonant cavity generate a 180° phase difference through two slot openings, thereby realizing a high-isolation filter crosser. Compared with the conventional orthogonal mode realization mode, the isolation is improved by 9 dB at the same bandwidth.

[0023] 2) The high-isolation multi-coupling-path substrate integrated waveguide filter crosser according to an embodiment of the present application is used to solve the problem of poor isolation at an absolute bandwidth of 1.44% or 4.75% in the prior art filter crosser realized by using orthogonal modes. The fifth resonant cavity is arranged at the center of the dielectric substrate, and the first resonant cavity, the second resonant cavity, the third resonant cavity and the fourth resonant cavity are arranged around the fifth resonant cavity. The fifth resonant cavity and the first resonant cavity, the second resonant cavity, the third resonant cavity and the fourth resonant cavity generate a 180° phase difference through two slot openings, thereby realizing a high-isolation filter crosser. Compared with the conventional orthogonal mode realization mode, the isolation is improved by 9 dB at the same bandwidth. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The figure is a structural schematic diagram of the high-isolation multi-coupling-path substrate integrated waveguide filter crosser according to an embodiment of the present application.

[0025] Figure 2 The figure is a magnetic coupling topological structure schematic diagram of the high-isolation multi-coupling-path substrate integrated waveguide filter crosser according to an embodiment of the present application.

[0026] Figure 3 The figure is a dielectric substrate structure schematic diagram of the high-isolation multi-coupling-path substrate integrated waveguide filter crosser according to an embodiment of the present application.

[0027] Figure 4 The figure is a schematic diagram of TE 101 and TE 102 / TE 201 modes excited by each resonant cavity of the high-isolation multi-coupling-path substrate integrated waveguide filter crosser according to an embodiment of the present application.

[0028] Figure 5 The figure is a frequency response curve of the high-isolation multi-coupling-path substrate integrated waveguide filter crosser according to an embodiment of the present application.

[0029] Reference numerals:

[0030] 1: first metal layer; 2: second metal layer; 3: dielectric substrate; 4: metalized via; 5: first input port; 6: second input port; 7: first output port; 8: second output port; 9: first resonant cavity; 10: second resonant cavity; 11: third resonant cavity; 12: fourth resonant cavity; 13: fifth resonant cavity; 14: slot opening. DETAILED DESCRIPTION

[0031] The application will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of the application will be more apparent from the following description and claims.

[0032] Embodiment one

[0033] Please refer to Figure 1 A high-isolation substrate integrated waveguide filter cross based on multiple coupling paths, comprising a first metal layer 1 and a second metal layer 2, a dielectric substrate 3 is arranged between the first metal layer 1 and the second metal layer 2; the first metal layer 1 is provided with a first input port 5, a first output port 7, a second input port 6 and a second output port 8; the dielectric substrate 3 is provided with a first resonant cavity 9, a second resonant cavity 10, a third resonant cavity 11, a fourth resonant cavity 12 and a fifth resonant cavity 13.

[0034] The first input port 5 excites the first resonant cavity 9, the first resonant cavity 9 and the fifth resonant cavity 13 realize multiple coupling paths through two slot openings 14, the fifth resonant cavity 13 and the third resonant cavity 11 realize multiple coupling paths through two slot openings 14, and the third resonant cavity 11 is coupled to the first output port 7 for output; the second input port 6 excites the second resonant cavity 10, the second resonant cavity 10 and the fifth resonant cavity 13 realize multiple coupling paths through two slot openings 14, the fifth resonant cavity 13 and the fourth resonant cavity 12 realize multiple coupling paths through two slot openings 14, and the fourth resonant cavity 12 is coupled to the second output port 8 for output.

[0035] Through the above connection mode, the effect diagram as shown in Figure 2 is formed. Figure 2 S1 and S2 in the figure are excitation sources, L1 and L2 are loads, and black circles are first resonant cavities, second resonant cavities, third resonant cavities, fourth resonant cavities, and black boxes are fifth resonant cavities.

[0036] In combination with Figure 1 , reference is made to Figure 3, the medium substrate 3 forms the first resonant cavity 9, the second resonant cavity 10, the third resonant cavity 11, the fourth resonant cavity 12 and the fifth resonant cavity 13 by setting a plurality of metalized vias 4. The length-width ratio of the first resonant cavity 9, the second resonant cavity 10, the third resonant cavity 11 and the fourth resonant cavity 12 is 1:2; and the length-width ratio of the fifth resonant cavity 13 is 1:1.

[0037] In combination Figure 1 , with reference to Figure 4 , as an embodiment, the first resonant cavity 9, the second resonant cavity 10, the third resonant cavity 11 and the fourth resonant cavity 12 generate TE101 mode, and the fifth resonant cavity 13 generates TE102 / TE201 mode.

[0038] Two slot openings are arranged on each side of the fifth resonant cavity, and the two slot openings 14 on each side are located at one-fourth of the side length and three-fourths of the side length, respectively. The fifth resonant cavity 13 generates a 180° phase difference with the first resonant cavity 9, the second resonant cavity 10, the third resonant cavity 11 and the fourth resonant cavity 12 through the two slot openings 14, so as to realize a high-isolation filter cross.

[0039] Embodiment two

[0040] Please refer to Figure 3 and Figure 4 , the center frequency of the high-isolation substrate integrated waveguide filter cross based on multiple coupling paths is controlled at 20GHz. The substrate material of the medium substrate is Rogers RO5880, the dielectric constant is 2.2, and the thickness is 0.508mm. The diameter of all the metalized vias on the medium substrate is d=0.5mm. The width w1 of the first resonant cavity 9, the second resonant cavity 10, the third resonant cavity 11 and the fourth resonant cavity 12 is 11.33mm, and the length l1 is 5.62mm. The length and width of the fifth resonant cavity 13 are both w1=11.33mm.

[0041] Please refer to Figure 5 , it can be known that the center frequency of the high-isolation substrate integrated waveguide filter cross based on multiple coupling paths is 20GHz. Under an absolute bandwidth of 1.44%, the return loss is better than 20dB, and the isolation is better than 39dB.

[0042] The high-isolation substrate integrated waveguide filter cross based on multiple coupling paths has a compact structure and high space utilization rate. Compared with the traditional orthogonal mode implementation, the isolation is improved by 9dB under the same bandwidth.

[0043] The embodiments of the application are described in detail above with reference to the drawings, but the application is not limited to the above-described embodiments. Even if various changes are made to the application, as long as the changes fall within the scope of the claims of the application and equivalent technologies, they still fall within the protection scope of the application.

Claims

1. A high-isolation multi-coupled-path substrate integrated waveguide filter cross, characterized in that, The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. Wherein the first resonant cavity, the second resonant cavity, the third resonant cavity, the fourth resonant cavity work in TE 101 mode, and the fifth resonant cavity works in TE 102 or TE 201 mode.

2. The multi-coupling-path high-isolation substrate integrated waveguide filter crossbar of claim 1, wherein, The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter.

3. The multi-coupled path, high-isolation, substrate integrated waveguide filter crossbar of claim 2, wherein, The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter.

4. The multi-coupled path, high-isolation, substrate integrated waveguide filter crossbar of claim 1, wherein, The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path millimeter-wave filter. The application relates to a high-isolation-degree multi-coupling-path mill

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