Orthogonal joint shared by multiple frequency bands

Abstract

The invention discloses a multi-band common orthogonal head, and belongs to the technical field of microwave communication. The invention discloses a four-way symmetrical waveguide filter which comprises an axial multi-frequency shared waveguide assembly and four side wall branch waveguides, the axial multi-frequency shared waveguide assembly comprises a coupling waveguide, a corrugated groove gasket and a high-frequency waveguide, the side wall branch waveguides are uniformly distributed in a four-way symmetrical mode relative to the multi-frequency shared waveguide assembly, and each side wall branch waveguide comprises an evanescent mode filter and an impedance conversion section. The antenna has the advantages of being large in bandwidth, small in frequency band interval, compact in structure and easy to machine. According to the invention, the problems of mixed-mode suppression, small-frequency-band interval electrical design and difficult processing of a millimeter wave band structure during ultra-wideband use are solved, the influence of a high-order mode on a directional diagram of a feed source system can be effectively improved, the cross polarization of the antenna is reduced, and the antenna is suitable for engineering popularization.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of microwave communication technology, in particular to a multi-band shared quadrature junction which can be used as a waveguide quadrature junction shared by multi-band. BACKGROUND

[0002] In the field of microwave antenna communication, multi-band sharing is an important means to increase the function of the antenna and reduce the construction cost of the antenna. As an important part of determining the performance of the antenna, the design of the multi-band shared quadrature junction which realizes the multi-band frequency separation function is particularly critical.

[0003] The multi-band shared feed network system with more than twice frequency mainly includes coaxial type and common jet type. The high and low frequency signals of the coaxial quadrature junction are transmitted in different channels inside and outside, which are physically isolated. Therefore, the design is relatively easy. However, the common jet quadrature junction is designed with high and low frequency signals mixed in the axial center waveguide. Therefore, the high frequency signal transmission channel is a serious overmoded structure. Any structural discontinuity can easily cause the excitation of high-order modes, thereby seriously deteriorating the performance indicators. This results in a greater difficulty in designing the common jet quadrature junction. In addition, the design of this type of device has a large mutual influence between different frequency bands, a large relative bandwidth, many structural parameters, a large calculation scale, and difficulty in simulation optimization. There are few detailed design introductions of the common jet type ultra-wideband multi-band shared quadrature junction in the current public literature, especially the design of small frequency band intervals. This also limits the development of multi-band shared common jet feed network. SUMMARY

[0004] Therefore, the present application provides a multi-band shared quadrature junction. The present application can realize the function of separating the frequency bands of more than twice frequency multi-band signals working simultaneously, and especially solve the problem of designing small frequency band intervals.

[0005] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0006] A multi-band shared quadrature junction is a six-port microwave device, which includes an axial multi-band shared waveguide assembly and four side wall branch waveguides. The axial multi-band shared waveguide assembly is a high frequency signal transmission channel, which includes a coupling waveguide, a corrugated groove gasket and a high frequency waveguide. The side wall branch waveguides are uniformly distributed in four ways relative to the multi-band shared waveguide assembly, which are low frequency signal transmission channels.

[0007] Further, the inner cavity of the axial multi-frequency common waveguide assembly comprises three parts of a large-opening circular waveguide segment in the coupling waveguide, a spline transformation circular transition segment at the joint of the coupling waveguide and the high-frequency waveguide, and a small-opening circular waveguide segment in the high-frequency waveguide, wherein the spline transformation circular transition segment is provided with two corrugated groove structures at a position close to the small-opening circular waveguide segment, and the corrugated groove structures are pressed between the coupling waveguide and the high-frequency waveguide to form.

[0008] Further, the side wall branch waveguide is composed of an upper cover plate and a lower cover plate, and the inner cavity comprises a standard waveguide and a lost-mold filter, and the lost-mold filter and the standard waveguide are matched in impedance through a rectangular waveguide ladder transformer.

[0009] Further, the lost-mold filter comprises three groups of ridge waveguide segments symmetrically arranged upward and downward, wherein the first ridge waveguide segment is directly connected with the axial rectangular long hole of the coupling waveguide, and the second group of ridge waveguide segments is provided with a narrow slit waveguide stub at a central position, and the narrow slit waveguide stub is directed to one side of the upper cover plate or the lower cover plate of the side wall branch waveguide.

[0010] Further, two diagonal pins and holes are arranged on the upper cover plate or the lower cover plate of the side wall branch waveguide, so as to ensure the screwing precision and electrical contact of the upper cover plate and the lower cover plate.

[0011] The beneficial effects of the present application are as follows:

[0012] 1. The present application adopts a novel lost-mold filter architecture and a coupling structure, solves the problem of high-frequency high-order mode suppression when the frequency is more than 2 times under the premise of realizing low-frequency band pass matching, and realizes low-loss transmission in the high-frequency band.

[0013] 2. The present application adopts a side wall filter stub loading and straight path corrugated groove loading structure, realizes the problem of multi-frequency band electrical design with small frequency band interval, solves the contradiction problem of small frequency band interval and wide stop band design, and further expands the application space of the common nozzle feed system.

[0014] 3. The present application has the characteristics of large bandwidth and small frequency band interval, and has a compact structure, is easy to process, realizes good electrical performance in the Ka / Q / V frequency band, can effectively improve the influence of high-order modes on the directional diagram of the feed system and reduce the antenna cross polarization, is easy to expand to low-frequency band application, and is suitable for engineering promotion. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is the overall structure schematic diagram of the multi-frequency common orthogonal joint in the embodiment of the present application.

[0016] Figure 2 is a half-section schematic diagram of the axial multi-frequency common waveguide assembly.

[0017] Figure 3is a half profile schematic diagram of a single side wall branch waveguide.

[0018] Figure 4 is a structural schematic diagram of the upper cover plate and the lower cover plate of a single side wall branch waveguide.

[0019] Figure 5 is a main mode return loss frequency response curve of an embodiment of the present application.

[0020] Figure 6 is a main mode axial high frequency channel transmission loss frequency response curve of an embodiment of the present application.

[0021] Figure 7 is a main mode side wall branch low frequency channel transmission loss frequency response curve of an embodiment of the present application.

[0022] Reference signs: 1-axial multi-frequency shared waveguide assembly, 2-side wall branch waveguide, 11-coupling waveguide, 12-corrugated groove gasket, 13-high frequency waveguide, 21-upper cover plate, 22-lower cover plate. DETAILED DESCRIPTION

[0023] The technical solutions of the present application will be further described in detail below with reference to the accompanying drawings.

[0024] A multi-band shared quadrature junction is a six-port microwave device, comprising an axial multi-frequency shared waveguide assembly and four side wall branch waveguides. The axial multi-frequency shared waveguide assembly comprises a coupling waveguide, a corrugated groove gasket and a high frequency waveguide, and the high frequency signals are transmitted along the axial direction thereof; the side wall branch waveguides are uniformly distributed in four ways relative to the multi-frequency shared waveguide assembly, and are transmission channels for low frequency signals.

[0025] The inner cavity of the axial multi-frequency shared waveguide assembly comprises a large-opening circular waveguide section, a spline transformation circular transition section and a small-opening circular waveguide section, wherein the spline transformation circular transition section is provided with two corrugated groove structures at a position close to the small-opening circular waveguide section, and the structures are formed by being pressed between the coupling waveguide and the high frequency waveguide through the corrugated groove gasket.

[0026] The structure of the side wall branch waveguide comprises an upper cover plate and a lower cover plate, and the inner cavity comprises a standard waveguide and a lost mode filter. The lost mode filter comprises three groups of ridge waveguide sections symmetrically arranged above and below, the first ridge waveguide section is directly connected to the axial rectangular slot of the coupling waveguide, and the second group of ridge waveguide sections is provided with a narrow slit waveguide stub at the center position, and the narrow slit waveguide stub is only directed to one side of the upper cover plate or the lower cover plate of the side wall branch waveguide. The lost mode filter and the standard waveguide are matched in impedance through a rectangular waveguide ladder transformer.

[0027] Two diagonal pins and holes are arranged on the upper cover plate or the lower cover plate of the side wall branch waveguide, so as to ensure the screwing precision and good electrical contact of the upper and lower cover plates.

[0028] A more specific example is as follows:

[0029] A multi-band shared quadrature junction, as shown in Figure 1 , comprises an axial multi-band shared waveguide assembly 1 and four side wall branch waveguides 2, the axial multi-band shared waveguide assembly 1 has two circular waveguide ports, and each of the four side wall branch waveguides 2 has a rectangular waveguide port, and each circular waveguide port has two degenerate main modes in electricity, so that the junction can be realized as an eight-port device in electricity.

[0030] As shown in Figure 2 , the multi-band shared waveguide assembly 1 comprises three parts of a coupling waveguide 1, a corrugated groove gasket 2 and a high-frequency waveguide 3, which are axially crimped by the three parts to form a two-stage corrugated groove cavity structure, and the gradual change of the circular waveguide aperture of the front and rear straight-through channels is realized through spline adaptive optimization.

[0031] The structure of a single side wall branch waveguide 2 is as shown in Figure 3 , which is formed by screwing the upper cover plate 21 and the lower cover plate 22 after positioning by pins. The ridge loading dimensions of the upper cover plate 21 and the lower cover plate 22 are the same. As shown in Figure 3 and Figure 4 , only the center position of the middle ridge of the upper cover plate 21 is provided with a transverse narrow slit waveguide branch. The four side wall branch waveguides 2 are uniformly distributed in four-way symmetry about the axis of the multi-band shared waveguide assembly.

[0032] The four coupling ports of the coupling waveguide 11 are directly connected to the ridge-loaded waveguide ports of the four side wall branch waveguides 2, and the end face of the coupling port is parallel to the axis of the multi-band shared waveguide.

[0033] As shown in Figure 3 and Figure 4 , the side wall branch waveguide electrically includes a disappearing mode filter and a stepped impedance transformer. The disappearing mode filter is designed with three ridges, and the stepped impedance transformer is a one-order rectangular waveguide stepped impedance transformer.

[0034] The working principle of the junction is as follows:

[0035] When the multi-band signals received by the feed are transmitted to the multi-band shared quadrature junction, the Ka-band radio frequency signals are coupled to the side wall branch waveguide at the coupling port of the coupling waveguide side wall, and then transmitted to the rear Ka radio frequency channel through the matching waveguide section. The disappearing mode filter in the side wall branch waveguide realizes the suppression of Q-band and V-band coupled signals, and the gradually decreasing aperture of the axial multi-band shared waveguide assembly transmits the Q-band and V-band signals to the rear high-frequency channel with low loss while short-circuiting the Ka-band. The working principle is opposite when the multi-band signals are transmitted, which will not be described here.

[0036] The effects of the present application will be further described with reference to the accompanying drawings.

[0037] Case: A wide-band multi-frequency shared quadrature junction

[0038] Design frequency: Ka (side wall channel): 27.5-31 GHz.

[0039] Q / V (straight channel): 37.5-52.5 GHz.

[0040] The case structure is shown in Figure 1 The main parameters are as follows:

[0041] The large diameter of the multi-frequency shared waveguide assembly 1 is D1=6.92mm; the small diameter is D2=5.3mm; the side wall branch waveguide 2 has a ridge waveguide inlet wide side W1=4.67mm, the coupling waveguide 11 has a coupling port width AOH1=5.33mm, and the narrow side B0H1=3.0mm.

[0042] After the detailed design of the multi-frequency shared quadrature junction, the final electrical simulation results are shown in Figures 5-7 As can be seen from Figure 5 , S11 is less than -22.5dB in the Ka band 27.5-31GHz, and S11 is less than -26dB in the Q / V band 37.5-52.5GHz, which is excellent. As can be seen from Figure 6 , the axial channel has better than 34dB suppression in the Ka band, and low-loss transmission is achieved in the Q / V band. Through analysis Figure 7 , it can be known that the side wall Ka branch waveguide has a suppression degree of the main mode of the Q / V band of more than 53dB, the Ka band single-arm coupling is -3dB, and 0dB low-loss coupling of double-arm symmetric single polarization can be achieved. As can be seen from the simulation results, the frequency band transition of the shared quadrature junction is designed to be 31GHz-37.5GHz, and a certain design margin is left, which can realize the engineering design of a multi-frequency shared quadrature junction with a small frequency band interval of 1.2:1 or less.

[0043] The multi-frequency shared quadrature junction is a complex microwave device that integrates frequency multiplexer and wide-band quadrature function. It not only needs to meet the impedance matching of each high and low frequency band, but also needs to achieve high-level suppression between different frequency bands. The above-mentioned junction is designed for millimeter wave band, with a minimum working frequency of 27.5GHz and a maximum working frequency of 52.5GHz. For multi-frequency shared quadrature junctions above Ka band, the small size of the structure often seriously affects the process design and processing. However, this junction not only restricts the narrow side size of the coupling port of the coupling waveguide 11, the thickness of the ridge waveguide ridge of the side wall branch waveguide 2, and the wide groove width of the corrugated groove gasket 12, but also selects an easy-to-process coupling form and filter type, which ensures the effectiveness of the design. When extended to low frequency applications, it is easier to process.

[0044] The orthogonal joint has excellent electrical indicators, compact structure and easy process implementation. In the design of Ka / Q / V frequency band, the joint realizes low-loss side wall coupling of Ka frequency band signal and straight-through transmission of Q / V frequency band signal, and can be widely used in multi-frequency shared antenna design in the fields of satellite communication, reconnaissance and measurement and control.

[0045] In summary, the application comprises an axial multi-frequency shared waveguide assembly and four side wall branch waveguides. The axial multi-frequency shared waveguide assembly is composed of a coupling waveguide, a corrugated groove gasket and a high-frequency waveguide, and is a Q / V high-frequency transmission channel. The side wall branch waveguides are uniformly distributed in four-way symmetry relative to the multi-frequency shared waveguide assembly, and are Ka low-frequency coupling transmission channels. The application solves the design contradiction problem of more than 2 times frequency use, wide stop band and small frequency band interval, and simultaneously takes into account the high-order mode suppression and the problem of too small structure size of millimeter wave band difficult to process. The application has the advantages of compact structure, excellent indicators and the like, and can be conveniently extended to the design of low-frequency antenna multi-frequency sharing, and meets the use requirements of most satellite communication station type antennas.

[0046] It should be noted that the above description and cases are helpful for those skilled in the art to understand the application, but do not limit the protection scope of the application. Any implementation of various modifications, scaling, modification, improvement and / or deletion and simplification without departing from the essential content of the application shall fall within the protection scope of the application.

Claims

1. A multi-band shared orthogonal connector, characterized in that, It is a six-port microwave device, including an axial multi-frequency shared waveguide assembly and four sidewall branch waveguides; the axial multi-frequency shared waveguide assembly is the high-frequency signal transmission channel, including a coupling waveguide, a corrugated groove gasket and a high-frequency waveguide; the sidewall branch waveguides are symmetrically and uniformly distributed in four directions relative to the multi-frequency shared waveguide assembly, and are the low-frequency signal transmission channels.

2. The multi-band shared orthogonal connector according to claim 1, characterized in that, The inner cavity of the axial multi-frequency shared waveguide assembly comprises three parts: a large-aperture circular waveguide segment in the coupled waveguide, a spline-transformed circular transition segment at the junction of the coupled waveguide and the high-frequency waveguide, and a small-aperture circular waveguide segment in the high-frequency waveguide. The spline-transformed circular transition segment has two corrugated groove structures near the small-aperture circular waveguide segment. The corrugated groove structures are formed by pressing the corrugated groove gaskets between the coupled waveguide and the high-frequency waveguide.

3. The multi-band shared orthogonal connector according to claim 1, characterized in that, The sidewall branch waveguide consists of an upper cover plate and a lower cover plate. The inner cavity includes a standard waveguide and a lost mode filter. Impedance matching between the lost mode filter and the standard waveguide is achieved through a rectangular waveguide step converter.

4. A multi-band shared orthogonal connector according to claim 3, characterized in that, The vanishing mode filter contains three sets of symmetrical ridge waveguide segments. The first ridge waveguide segment is directly connected to the axial rectangular slot of the coupling waveguide. A slit waveguide stub is set at the center of the second ridge waveguide segment, and the slit waveguide stub faces the upper or lower cover plate of the sidewall branch waveguide.

5. A multi-band shared orthogonal connector according to claim 3, characterized in that, The upper or lower cover plate of the sidewall branch waveguide is provided with two diagonal pins and holes to ensure the screw connection accuracy and electrical contact of the upper and lower cover plates.

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