A KAQV multi-frequency shared power distributor

Abstract

The invention discloses a KAQV multi-frequency shared power distributor, which belongs to the field of waveguide technology. It includes an axial multi-frequency shared waveguide and four sidewall branch waveguides. The axial multi-frequency shared waveguide is a signal transmission channel for the Ka transmitting frequency band and the QV frequency band. The sidewall branch waveguides for transmitting the Ka receiving frequency band signals are distributed along the axial direction, and the sidewall branch waveguides are distributed in a four-way symmetrical manner relative to the axial multi-frequency shared waveguide. Each sidewall branch waveguide includes a filter and a step waveguide impedance converter, and the filter is a two-stage filter cascade design. The present invention has the characteristics of large relative bandwidth, low cross-polarization, and low standing wave ratio, and has a compact structure and is easy to process. The present invention solves the problem of difficulty in suppressing high-order modes when used over 2 times the frequency and the problem of the Ka-band structure being too small to be processed, and at the same time completes low-frequency broadband impedance matching. In a bandwidth close to 3 times the frequency, it can effectively improve the influence of high-order modes on the radiation pattern of the feed system and reduce the level of antenna cross-polarization, which is suitable for engineering promotion.

Description

Technical Field

[0001] The present invention relates to the field of waveguide technology, and in particular to a multi-frequency shared power distributor that satisfies Ka transceiver, Q and V requirements. Background Art

[0002] In the field of microwave antenna communications, power division networks and power synthesis networks are common passive subsystems in various station-type antenna feeding networks. In order to achieve multiple uses of one station and multiple frequencies, reduce antenna construction costs, and increase antenna usage functions, users are increasingly demanding multi-frequency shared antennas, making the design of microwave devices that include frequency separation and power distribution even more important.

[0003] At present, there are two main forms of multi-frequency shared feed network systems: coaxial wave splitting and common nozzle wave splitting. Among them, coaxial wave splitting has developed to a certain bottleneck period, and the common nozzle wave splitting form is more traditional, but it has more advantages for the comprehensive use indicators of antennas. At the same time, it is well known that the number of high-order mode excitations of multi-frequency co-jet devices increases sharply with the increase of relative bandwidth. These high-order modes directly affect the electrical design indicators of the highest frequency and secondary high frequency bands. The antenna pattern and cross-polarization will be extremely deteriorated. Different high-order modes have different directions and degrees of influence on the feed network system. There are few reports on the control methods of these large numbers of harmful high-order modes. Therefore, there has been no systematic introduction to the design of mature multi-frequency shared power dividers internationally, which has correspondingly curbed the development of multi-frequency co-jet feed networks. Therefore, it is imperative to break through technical barriers and find new methods for designing new dual-frequency or multi-frequency shared power dividers. Summary of the invention

[0004] The purpose of the present invention is to provide a KAQV multi-frequency shared power divider, which can solve the problems of difficulty in suppressing high-order modes, difficulty in processing, poor antenna cross polarization, and difficulty in meeting engineering use requirements of multi-frequency co-spray power dividers with bandwidths exceeding twice or three times the frequency above the Ka band. The power divider has excellent electrical indicators such as large bandwidth, low cross polarization, and low standing wave ratio, and has many advantages such as compact structure, easy processing, and simple process design.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A KAQV multi-frequency shared power distributor is a six-port microwave device, comprising an axial multi-frequency shared waveguide and four side wall branch waveguides; the axial multi-frequency shared waveguide is a circular transition waveguide, and high-frequency band signals (Ka transmission band and QV band signals) are transmitted along its axial direction; the four side wall branch waveguides are symmetrically distributed at 90 degrees along the axial direction of the axial multi-frequency shared waveguide, and are transmission channels for low-frequency band signals (Ka reception band signals); four rectangular ridged coupling ports are opened on the inner wall of the axial multi-frequency shared waveguide, and the four rectangular ridged coupling ports are symmetrically distributed at 90 degrees around the axis of the multi-frequency shared waveguide and correspond one to one to the four side wall branch waveguides; the four side wall branch waveguides each comprise a filter and a stepped impedance converter.

[0007] Furthermore, the gradual change curve of the circular transition waveguide is a spline fitting curve.

[0008] Furthermore, the rectangular long side of the rectangular ridged coupling port is along the axial direction, and the end surface of the rectangular ridged coupling port is parallel to the axis of the multi-frequency shared waveguide.

[0009] Furthermore, the filter of the sidewall branch waveguide is a two-stage filter cascade structure; the first-stage filter of the two-stage filter cascade structure is a block mode filter, and the coupling port of the first-stage filter adjacent to the multi-frequency shared waveguide has only one row of metal vertical teeth along the branch waveguide direction; the second-stage filter of the two-stage filter cascade structure is a transverse corrugated groove filter with high and low impedance changes.

[0010] Furthermore, the entrance of the first-stage filter is a rectangular cavity structure.

[0011] Furthermore, the sidewall branch waveguide ladder impedance transformer is a first-order rectangular waveguide ladder impedance transformer.

[0012] The beneficial effects of the present invention compared with the background technology are:

[0013] 1. Electrically, the present invention, through a novel branch filter structure and coupling port design, can make the coupling of the main mode of the high-frequency over-modulation section to each higher-order mode below -20dB when the maximum relative bandwidth is close to 3 times the frequency, solve the problem of a large number of high-order mode mutual coupling when the frequency is used exceeding 2 times, improve the high-frequency channel return loss, reduce the linear polarization cross-polarization components of the high-frequency channel, and suppress the high-order harmonics of the low-frequency passband.

[0014] 2. The second-stage filter in the cascade filter of the present invention adopts a transverse corrugated groove filter with high and low impedance variations, constrains the coupling port gap and microstructure size, and reasonably sets the edge chamfers, thereby greatly reducing the processing difficulty of millimeter wave band devices and having engineering feasibility.

[0015] 3. The multi-frequency shared power distributor of the present invention is reasonably designed and suitable for engineering application and promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of a four-wall coupled multi-frequency shared power distributor in an embodiment of the present invention.

[0017] Figure 2 It is a three-dimensional assembly schematic diagram of a multi-frequency shared power distributor in an embodiment of the present invention.

[0018] Figure 3 It is a schematic diagram of the axial circular transition and side wall coupling oral body in an embodiment of the present invention.

[0019] Figure 4 3D structure and cross-sectional view of the sidewall branch waveguide in an embodiment of the present invention.

[0020] Figure 5 It is a front view of the cross section of the side wall branch waveguide in an embodiment of the present invention.

[0021] Figure 6 (a) to Figure 6 (c) are the return loss frequency response curves of the main mode operating frequency band.

[0022] Figure 7 (a) ~ Figure 7 (b) are the frequency response curves of the main mode and the high-order mode coupling in the high-frequency band. In the figure, only the curves of the worst indicators are distinguished, namely S1(7),1(1) and S1(9),1(1). It can be seen from the figure that even the worst indicators have good effects.

[0023] FIG8 (a) to FIG8 (b) are frequency response curves of the low-frequency port of the coupling branch to the high-frequency signal isolation.

[0024] Explanation of the reference numerals: 1—axial multi-frequency common waveguide, 2—sidewall branch waveguide, 3—first-stage filter, 4—second-stage filter, 5—step impedance transformer. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings.

[0026] A KAQV multi-frequency shared power distributor is a six-port microwave device, comprising an axial multi-frequency shared waveguide and four side wall branch waveguides, wherein the axial multi-frequency shared waveguide is a Ka transmitting frequency band and QV frequency band signal transmission channel, and the side wall branch waveguide is a Ka receiving frequency band signal transmission channel; the axial multi-frequency shared waveguide is a circular transition waveguide, and high-frequency band signals are transmitted along its axial direction; the four side wall branch waveguides are symmetrically distributed at 90 degrees along the axial direction of the multi-frequency shared waveguide, and are low-frequency band signal transmission channels; the side wall branch waveguides each comprise a filter and a stepped impedance converter.

[0027] Wherein, the axial circular transition waveguide gradient curve is designed by spline fitting.

[0028] Four rectangular ridged coupling ports are provided on the inner wall of the axial multi-frequency shared waveguide and are symmetrically distributed at 90° around the axis of the multi-frequency shared waveguide. The long sides of the rectangles are along the axis direction, and the end faces of the coupling ports are parallel to the axis of the multi-frequency shared waveguide.

[0029] The filter of the side wall branch waveguide is a two-stage filter cascade design; the first stage filter in the cascade filter is a fast mode filter, and there is only one row of metal vertical teeth close to the multi-frequency shared waveguide coupling port along the branch waveguide direction, and the second stage filter in the cascade filter is a transverse corrugated groove filter with high and low impedance changes.

[0030] The inlet of the first-stage block mode filter is a rectangular cavity structure, rather than having symmetrical metal sawtooth structures distributed above and below.

[0031] The sidewall branch waveguide ladder impedance transformer is a first-order rectangular waveguide ladder impedance transformer.

[0032] The multi-frequency shared power divider has the characteristics of large relative bandwidth, low cross-polarization, low standing wave ratio, compact structure and easy processing. The multi-frequency shared power divider solves the problem of difficulty in suppressing high-order modes when used at frequencies exceeding 2 times the frequency and the problem of the Ka-band structure being too small to be processed, while completing low-frequency broadband impedance matching. In a bandwidth close to 3 times the frequency, it can effectively improve the influence of high-order modes on the radiation pattern of the feed system and reduce the level of antenna cross-polarization, which is suitable for engineering promotion.

[0033] The multi-frequency shared power divider has always been the most critical component of the multi-frequency network. From the functional point of view, it needs to complete the high isolation separation of multiple frequency bands, and also realize the orthogonal polarization separation of a single frequency band and the equal power distribution of a single polarization. It can be said that it integrates the main functions of the traditional frequency duplexer and the broadband orthogonal mode coupler. Figure 1 As shown, from a physical point of view, the power divider is a tapered six-port device, and from an electrical point of view, the power divider is an 8-port device with two orthogonal polarizations in input and output.

[0034] For multi-frequency shared distributors above the Ka band, the process design and processing are often seriously affected due to the small structure size. The present invention not only constrains the small-size structure parameters during design, but also selects coupling forms and filter types that are easy to process, thereby ensuring the effectiveness of the design.

[0035] Specifically, Figure 2 As shown in FIG. 1 , the multi-band shared power divider includes an axial multi-band shared waveguide and four sidewall branch waveguides. Figure 3As shown, the axial multi-frequency shared waveguide mainly includes two design partitions, namely, a circular transition and a sidewall coupling port. In order to suppress axial high-order mode excitation, the circular transition curve is designed using a spline fitting curve.

[0036] The circular transition curve is provided with four rectangular ridge coupling ports, which are symmetrically distributed at 90° around the axis of the multi-frequency common waveguide, with the long sides of the rectangles along the axis direction, and Figure 1 As shown, the coupling port end face is parallel to the axis of the multi-frequency shared waveguide.

[0037] Further, such as Figure 5 As shown, the side wall branch waveguide includes a filter and a stepped impedance converter. The filter of the side wall branch waveguide is a two-stage filter cascade design; the first stage filter in the cascade filter is a fast mode filter, and there is only one row of metal vertical teeth along the branch waveguide direction close to the multi-frequency shared waveguide coupling port, and the second stage filter in the cascade filter is a transverse corrugated slot filter with high and low impedance changes. The stepped impedance converter is a first-order rectangular waveguide stepped impedance converter, which eventually converts the branch waveguide to the corresponding coupling frequency band standard BJ220 outlet. As shown Figure 4 As shown, the inlet of the first-stage block mode filter is a rectangular cavity structure, rather than a symmetrical metal sawtooth structure distributed above and below.

[0038] Furthermore, the longitudinal slot unit of the block mode filter has a natural suppression characteristic for the higher-order modes of the rectangular waveguide, and has ultra-wide channel and power capacity characteristics. By selecting a reasonable cutoff frequency, it can meet the design requirements of engineering stopband exceeding three times the frequency.

[0039] like Figure 1 As shown, the working principle of the multi-band shared power divider is as follows:

[0040] Usually when multiple frequency signals are received simultaneously, the RF signal transmitted to the multi-frequency common waveguide passes through the side wall coupling port, and the Ka receiving frequency band signal is coupled and matched by the branch block mode filter at 0dB, and the Ka transmitting frequency band and QV frequency band are short-circuited and suppressed, and then transmitted to the back-end waveguide routing through the low-frequency step impedance converter, and the highest frequency signal of the Ka transmitting frequency band and QV band is output from the axial channel with low loss. The working principle is opposite when transmitting multi-frequency signals, so it will not be repeated.

[0041] For ease of understanding, a specific KAQV multi-frequency shared power distributor is taken as an example, and the effects of the present invention are auxiliary explained in conjunction with the corresponding drawings.

[0042] Example: KaQV multi-frequency shared power divider

[0043] The design frequency is Ka: 17.7GHz~21.2GHz; 27.5~31GHz.

[0044] QV: 37.5GHz~42.5GHz; 47.2~51.4GHz.

[0045] The structure of KaQV multi-frequency shared power divider is as follows Figure 1 As shown, the corresponding values ​​of the main structural parameters are as follows:

[0046] The diameter of the large round transition opening is D1=11.6mm; the diameter of the small opening is D2=7.2mm; the wide side of the Ka-band filter entrance is W1=8.8mm, and the width of the rectangular ridge coupling opening is AOH1=5.15mm.

[0047] Figures 6 to 8 show the simulation results of the multi-frequency shared power divider. The bandwidth used by the power divider is close to the triple frequency. As can be seen from Figures 6 (a) to (c), the main mode return loss S in the Ka receiving band is 1(1)1(1) Less than -23dB, Ka transmission band and QV band are axial transmission channel main mode return loss S 1(1)1(1) As shown in Figure 7 (a) to (b), the mutual coupling energy from the main mode to the nth higher-order mode mainly returns to the common port, with S 1(n)1(1) It shows that the coupling degree is less than -40dB in the Ka transmission frequency band. In the QV frequency band, due to the higher frequency band, the number of excited high-order modes is greater, and the maximum coupling degree is less than -20dB. As can be seen from Figure 8 (a) to (b), the frequency band isolation of the main mode in different high-frequency bands is S 3(1)1(1) It means that the suppression degree of low frequency band on high frequency band is greater than 60 dB for the main mode of Ka receiving band on Ka transmitting band and greater than 80 dB for the main mode of QV band in the side wall branch waveguide.

[0048] In summary, the present invention includes an axial multi-frequency shared waveguide and four sidewall branch waveguides. The axial multi-frequency shared waveguide is a signal transmission channel for the Ka transmitting frequency band and the QV frequency band. The sidewall branch waveguides for transmitting the Ka receiving frequency band signals are distributed along the axial direction, and the sidewall branch waveguides are distributed in four-way symmetrical manner relative to the axial multi-frequency shared waveguide. The present invention solves the problems of difficulty in suppressing high-order modes when the frequency exceeds 2 times and the problem of the Ka-band structure being too small to be processed. It has excellent electrical indicators such as large relative bandwidth, low cross-polarization, and low standing wave ratio, and has many advantages such as compact structure and easy processing. It completes the core issues of frequency separation, polarization separation, and power distribution when the antenna is used for multi-frequency co-spraying, and can meet the needs of most multi-frequency broadband fixed stations and vehicle-mounted stations.

[0049] It should be noted that the above description and examples are helpful for those skilled in the art to understand the invention, but they do not limit the protection scope of the invention. Any various deformations, scaling, modifications and / or simplifications that do not deviate from the essence of the invention should fall within the protection scope of the invention.

Claims

1. A KAQV multi-frequency shared power divider is a six-port microwave device, comprising an axial multi-frequency shared waveguide and four sidewall branch waveguides; characterized in that: The axial multi-frequency shared waveguide is a circular transition waveguide, and the Ka transmission frequency band and QV frequency band signals are transmitted along its axial direction; the four side wall branch waveguides are symmetrically distributed at 90° along the axial direction of the axial multi-frequency shared waveguide, and are transmission channels for the Ka reception frequency band signals; four rectangular ridged coupling ports are opened on the inner wall of the axial multi-frequency shared waveguide, and the four rectangular ridged coupling ports are symmetrically distributed at 90° around the axis of the multi-frequency shared waveguide, and correspond to the four side wall branch waveguides one by one; the four side wall branch waveguides each include a filter and a stepped impedance converter; The gradient curve of the circular transition waveguide is a spline fitting curve; The rectangular long side of the rectangular ridged coupling port is along the axial direction, and the end surface of the rectangular ridged coupling port is parallel to the axis of the multi-frequency shared waveguide; The filter of the sidewall branch waveguide is a two-stage filter cascade structure; the first-stage filter of the two-stage filter cascade structure is a block mode filter, and the coupling port of the first-stage filter adjacent to the multi-frequency shared waveguide has only one row of metal vertical teeth along the branch waveguide direction; the second-stage filter of the two-stage filter cascade structure is a transverse corrugated groove filter with high and low impedance changes.

2. A KAQV multi-frequency shared power distributor according to claim 1, characterized in that: The entrance of the first-stage filter is a rectangular cavity structure.

3. A KAQV multi-frequency shared power distributor according to claim 1, characterized in that: The sidewall branch waveguide ladder impedance transformer is a first-order rectangular waveguide ladder impedance transformer.

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