CN102800993A - Dual-band wave beam equalization side-fed offset cassegrain antenna and realization method thereof - Google Patents

Abstract

The invention relates to a dual-band beam equalization side-fed offset Cassegrain antenna and its realization method. The antenna includes four standard side-fed offset Cassegrain antennas, and each pair of antennas includes a main reflector and a secondary reflector. Four sets of side-fed biased Cassegrain antennas are in the standard form, shared by transceivers, and each feed assembly is composed of multiple spline-shaped optical wall horn feeds, each spline-shaped The light wall horn feed is formed by sequential connection of spline-shaped light wall horn, square-circle transition, circular polarizer, square-square transition and orthogonal mode coupler. The main lobe of the low-frequency transmission pattern and the high-frequency reception pattern The first side lobe irradiates the reflector, and the phase center of the feed source assembly should be located on the focal plane of the reflector, and point to the center of the equivalent reflection surface. The invention makes the antenna transmit and receive patterns have equal beam widths, and the structure is simple. , Lightweight, easy to design, excellent performance, strong practicability, etc., and has good anti-interference ability of the same frequency.

Description

A dual-band beam equalization side-fed biased Cassegrain antenna and its implementation method

technical field

The invention relates to a dual-band beam equalization side-feed offset Cassegrain antenna and a realization method thereof, belonging to the technical field of antennas.

Background technique

With the rapid growth of demand for satellite broadband multimedia services, the relatively idle Ka-band replaces C-band and Ku-band and becomes the preferred frequency band for high-definition TV and broadband multimedia two-way services all over the world, especially in Europe and the United States. At present, most Ka-band broadband multimedia communication satellites use high-gain multi-beam antennas, and adopt multi-color multiplexing to achieve large capacity and wide coverage. In addition, in order to obtain high-efficiency transmission, multi-beam antennas are required to have low sidelobe characteristics to reduce interference between beams of the same frequency.

Space-borne high-gain low-sidelobe multi-beam antennas mainly include direct phased array antennas and reflector + array feed antennas. The beamforming network of the direct phased array antenna is complicated. When multiple beams are formed, the channel components multiply, which eventually leads to the weight, power consumption and heat consumption of the entire phased array antenna, and its operating frequency bandwidth is limited. Single-aperture single-feed sub-beams form multi-beams, which have low efficiency and high sidelobes; single-aperture multi-feeds are optimized to synthesize multi-beams. When the number of beams required by the system is large, the feed network is complex and requires a large amount of phase-shift attenuation Components and control components are more difficult to implement; multi-aperture single-feed sub-beams form multiple beams, and each caliber antenna can choose a larger caliber horn feed source, and the beams formed by the feed arrays corresponding to different caliber antennas are arranged at intervals, no need A complex feeding network can achieve high gain and low sidelobe seamless coverage.

At present, there are two main types of Ka-band multi-aperture single-feed multi-beam antennas used on the satellite: separate transceivers and shared transceivers. In the form of separate transmission and reception, a set of antenna feeder system is used for each frequency band of the transceiver, and the electrical dimensions of the transceiver antenna are equivalent, so as to obtain the consistency of the beam width of the transceiver; Dichroic materials or stepped rings are used to transmit or cancel high-frequency electromagnetic waves at the edge of the reflector, so that the electrical dimensions of the receiving and transmitting antennas are equivalent, and the consistency of the transmitting and receiving beam width is obtained. The former has larger mass and volume, and the structure is more complicated; the latter reflector is more difficult to process.

Due to the limitations of the existing satellite platform, there are strict requirements on the envelope size and structural characteristics of the antenna, so it is difficult to meet the requirements of the multi-beam antenna with separate transmission and reception; and the current multi-beam transmission and reception using dichroic materials and stepped circular reflectors For the antenna, the processing technology of the reflector is complex, and the electrical performance of the antenna deteriorates sharply under the condition of thermal deformation, so it is also difficult to meet the requirements.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art, to provide a dual-band beam equalization side-fed biased Cassegrain antenna, by using the main lobe of the low-frequency transmission pattern of the feed source and the first lobe of the high-frequency reception pattern One side lobe irradiates the reflector, so that the antenna transmit and receive pattern has equal beam width, which has the advantages of simple structure, light weight, easy design, excellent performance, strong practicability, etc., and has good anti-interference ability of the same frequency.

Another object of the present invention is to provide a method for realizing a dual-band beam equalization side-fed biased Cassegrain antenna.

Above-mentioned purpose of the present invention is mainly achieved through the following technical solutions:

A dual-band beam equalized side-fed offset Cassegrain antenna, including four standard side-fed offset Cassegrain antennas distributed on the satellite, each standard side-fed offset Cassegrain antenna includes a main The reflector, the sub-reflector, the feed source assembly, the first deployment mechanism and the second deployment mechanism, wherein the main reflector is connected with the sub-reflector through the second deployment mechanism, and the main reflector is connected to the satellite through the first deployment mechanism. Above, the feed assembly includes n spline shaped light wall horn feeds, each spline shaped light wall horn feed points to the sub-reflector, and the phase center of each spline shaped light wall horn feed Placed on the focal plane of the standard side-fed biased Cassegrain antenna, and pointing to the center of the equivalent reflector, each spline-shaped light-wall horn feed consists of a spline-shaped light-wall horn, a square-circle transition, and a circular polarization The first sidelobe of the Ka-band pattern and the main lobe of the K-band pattern of the spline shaped light wall horn -12~-15dB are located at the standard side feed bias Set the Cassegrain antenna at the feed illumination angle θ _a , where n is a positive integer, n≥8.

In the above dual-band beam equalized side-fed biased Cassegrain antenna, the spline-shaped light wall horn is based on the feed irradiation angle _{θ a} of the standard side-fed biased Cassegrain antenna and the spline-shaped light wall The maximum diameter D _f of the horn feed source is designed, and the maximum diameter D _f of the spline shaped light wall horn feed source is calculated according to the satellite communication coverage area and the four-color multiplexing plan.

In the above-mentioned dual-band beam equalization side-fed biased Cassegrain antenna, the first side lobe of the Ka-band 1.6GHz working frequency band pattern of the spline-shaped light wall horn is the main pattern of the K-band 1.6GHz working frequency band Lobe -12 ~ -15dB are all located at the feed source irradiation angle _{θ a} of the standard side-fed biased Cassegrain antenna.

In the above-mentioned dual-band beam equalization side-fed biased Cassegrain antenna, the feed components in the four standard side-fed biased Cassegrain antennas can contain the same number of spline-shaped optical wall horn feeds or not the same.

A method for realizing a dual-band beam equalization side-fed biased Cassegrain antenna, comprising the following steps:

Step 1: According to the antenna size required by the satellite platform, design four standard side-fed biased Cassegrain antennas to obtain the feed irradiation angle θ _a ;

Step 2: Calculate the maximum aperture D _f of the feed source according to the satellite communication coverage area and the four-color multiplexing plan;

Step 3: According to the feed irradiation angle θ _a of the standard side-fed biased Cassegrain antenna obtained in the first step and the feed aperture D _f obtained in the second step, design a spline-shaped optical wall horn, so that The first side lobe of the Ka-band pattern and the main lobe of the K-band pattern -12～-15dB of the shaped light wall horn are located at θ _a ;

Step 4: Connect the spline-shaped light-wall horn obtained in the third step with the square-circle transition, circular polarizer, square-square transition, and orthogonal mode coupler in order to obtain the feed source of the spline-shaped light-wall horn, n A spline-shaped light wall horn feed forms a feed assembly, and a total of four feed assemblies are formed, where n is a positive integer, n≥8

Step 5: Install the feed assembly obtained in step 4 into the standard side-fed offset Cassegrain antenna obtained in the first step, and install one feed assembly for each standard side-fed offset Cassegrain antenna. And make the phase center of each spline-shaped light wall horn feed be placed on the focal plane of the standard side-fed biased Cassegrain antenna, and point to the center of the equivalent reflective surface.

In the implementation method of the above-mentioned dual-band beam equalization side-fed biased Cassegrain antenna, in the third step, the first side lobe of the Ka-band 1.6GHz working frequency band of the spline-shaped light-wall horn is the same as that of the K-band 1.6 The main lobe of the pattern in the GHz working frequency band -12~-15dB is located at the feed source irradiation angle _{θ a} of the standard side-fed biased Cassegrain antenna.

In the implementation method of the above-mentioned dual-band beam equalization side-fed biased Cassegrain antenna, the number of spline-shaped light wall horn feeds contained in the four feed components in the fourth step may be the same or different.

Compared with the prior art, the present invention has beneficial effects as follows:

(1) The present invention creatively uses the main lobe of the low-frequency transmission pattern of the feed source and the first side lobe of the high-frequency reception pattern to illuminate the reflector, so that the antenna transmission and reception patterns have equal beam widths, and realize the sharing of transmission and reception. Compared with the separate antenna system, it has the advantages of simple structure and light weight. Compared with the current transceiver shared antenna system, it has the advantages of simple principle, convenient processing and easy realization, and has great technological progress;

(2) The present invention uses the standard side-fed biased Cassegrain antenna, which avoids problems such as the difficulty in designing the dichroic material of the existing transmitting and receiving common antenna and the stepped circular reflector and the complicated processing technology, and the processing of the reflecting surface is simple, and the thermal Under the condition of deformation, the influence on the electrical performance is small;

(3) The feed source used in the present invention is formed by sequential connection of spline-shaped dual-band light wall horn, square-circle transition, circular polarizer, square-square transition, and orthogonal mode coupler, wherein the spline-shaped dual-band light wall Compared with the existing speaker feed, the horn has a wide working bandwidth, 1.6GHz for transceiver, good symmetry, low cross polarization level, etc., and also has the advantage of good processing consistency;

(4) The antenna of the present invention adjusts the feed horn in the focal plane so that it points to the center of the equivalent reflection surface, so that the equalization of the edge beam and the center beam of the coverage area is realized, and the operation is convenient and easy;

(5) the antenna of the present invention has high gain and low side lobe characteristics, and has good anti-co-frequency interference capability, and simulation shows that its C/I (carrier-co-frequency interference ratio) is better than 14dB;

(6) The present invention solves the problem of equalization of transmitting and receiving beams, low sidelobe high gain and antenna electrical performance maintenance after partial focus, and can be applied to Ka frequency band transmitting and receiving shared antennas, multi-aperture multi-beam antennas, single-aperture multi-beam antennas, wide-angle Scanning antennas and other fields have a broad application field; and based on the characteristics of its own scheme, the antenna has the advantages of simple principle, easy design, excellent performance, convenient application and strong practicability. Angle-scanning reconnaissance satellites have strong practicality and market competitiveness.

Description of drawings

Fig. 1 is a schematic structural diagram of a four-aperture multi-beam antenna of the present invention;

Fig. 2 is a schematic structural diagram of a side-fed biased Cassegrain antenna of the present invention;

Fig. 3 is a schematic diagram of the spline control points of the spline-shaped dual-band light-wall horn of the present invention;

Fig. 4 is a schematic diagram of the structure of the spline-shaped dual-band light wall horn of the present invention;

Fig. 5 is a schematic diagram of the reflective surface irradiated by the receiving beam of the feed source of the present invention;

6 is a schematic diagram of the coverage area of the antenna of the present invention;

Fig. 7 is the simulation curve of the feed pattern of the spline-shaped dual-band light-wall horn of the present invention;

Fig. 8 is the simulation curve of the secondary pattern of the side-fed biased Cassegrain antenna of the present invention;

Fig. 9 is a schematic diagram of the direction of the feed source of the spline shaped light wall horn of the present invention;

Fig. 10a is a simulation curve diagram of the K-band defocus characteristic of the side-fed biased Cassegrain antenna of the present invention;

Fig. 10b is a simulation curve diagram of the Ka-band defocus characteristic of the side-fed biased Cassegrain antenna of the present invention;

Fig. 11 is a simulation curve diagram of C/I characteristics of the side-fed biased Cassegrain antenna of the present invention;

Among them, 1. Side-fed biased Cassegrain antenna; 2. Main reflector; 3. Sub-reflector; 4. Feed source component; 5. Spline shaped light wall horn feed; 6. Spline shaped Light wall horn; 7. Square-circle transition; 8. Circular polarizer; 9. Square-square transition; 10. Orthogonal mode coupler; 11. First deployment mechanism; 12. Second deployment mechanism.

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment the present invention is described in further detail:

The present invention uses a four-aperture side-fed offset Cassegrain antenna to realize the equalization of transmitting and receiving beams, the equalization of the coverage area edge beam and the central beam, and its structure is shown in Figure 1, including four standard side-fed offset Cassegrain antennas Cassegrain antenna 1 (A, B, C, D in Fig. 1), four pairs of side-fed biased Cassegrain antenna 1 is a standard form, shared by sending and receiving. Each antenna is composed of a main reflector 2, a sub-reflector 3, a feed assembly 4, a first deployment mechanism 11 and a second deployment mechanism 12, and the main reflector 2 and the sub-reflector 3 are connected through the second deployment mechanism 12 , the main reflector 2 is connected to the satellite through the first deployment mechanism 11, and each feed source assembly 4 includes n (n≥8) spline-shaped light wall horn feed sources 5 . In this embodiment, four standard side-fed biased Cassegrain antennas 1 have four feed source assemblies 4 in total. The number of spline-shaped light wall horn feed sources 5 in the four feed source assemblies 4 can be the same or different, for example, the four feed source assemblies 4 in this embodiment contain 10, 12, 10, and 8 samples respectively. Strip shaped light wall horn feed 5 . In the present embodiment, the feed source assembly 4 of antenna 1A and antenna 1C is respectively located on the two side walls of the satellite (only the feed source assembly 4 of antenna 1C can be seen in Fig. 1), and the feed source assembly 4 of antenna 1B and antenna 1D are located on the top diagonal of the satellite. FIG. 2 is a schematic structural diagram of the side-fed biased Cassegrain antenna of the present invention.

The specific implementation method of the dual-band beam equalization side-fed biased Cassegrain antenna in the embodiment of the present invention is as follows:

Step 1: According to the antenna size required by the satellite platform, design four standard side-fed biased Cassegrain antennas 1 to obtain the feed irradiation angle θ _a .

Step 2: Calculate the maximum aperture D _f of the feed source according to the satellite communication coverage area and the four-color multiplexing plan.

The third step: according to the feed irradiation angle θ _a of the standard side-fed biased Cassegrain antenna 1 obtained in the first step and the feed aperture D _f obtained in the second step, design the spline shaped light wall horn 6, Make the first sidelobe of the Ka-band 1.6GHz working frequency band of the spline-shaped light-wall horn 6 and the main lobe -12～-15dB of the K-band 1.6GHz working frequency band directional pattern both be located at θ _a .

Step 4: As shown in Figure 4, it is a schematic diagram of the structure of the spline-shaped dual-band light-wall horn of the present invention. It can be seen from the figure that each spline-shaped light-wall horn feed source 5 is composed of a spline-shaped light-wall horn 6, a radius Transition 7, circular polarizer 8, square transition 9 and orthogonal mode coupler 10. Connect the spline-shaped light-wall horn 6 obtained in the third step with the square-circle transition 7, circular polarizer 8, square-square transition 9 and orthogonal mode coupler 10 in order to obtain the spline-shaped light-wall horn feed 5 , using 10, 12, 10, and 8 spline-shaped light wall horn feeds 5 to form four feed assemblies 4, which are respectively used for A, B, C, and D four pairs of standard side feed offset Cassegrain Antenna 1 (see Figure 1). Fig. 3 is a schematic diagram of spline control points of the spline-shaped dual-band light-wall horn of the present invention.

Step 5: Install the feed assembly 4 obtained in the fourth step in the standard side-fed offset Cassegrain antenna 1 obtained in the first step, and install a feeder for each standard side-fed offset Cassegrain antenna 1 Source component 4, and make the phase center of each spline-shaped optical wall horn feed placed in the focal plane of the standard side-fed biased Cassegrain antenna 1, and point to the center of the equivalent reflective surface.

The antenna feed source of the present invention adopts the spline-shaped dual-band light-wall horn 6. This type of feed source has the advantages of good symmetry, low cross-polarization level, etc., and also has the advantage of good processing consistency. Owing to work in Ka/K dual frequency band, and the transmitting and receiving frequency bands all have the large operating bandwidth of 1.6GHz, and require consistent electrical performance in the whole frequency band, so the spline-shaped dual-band light-wall horn 6 of the present invention has a comparative advantage with traditional horns. big difference. By optimizing the spline function, adjusting the spline control points, etc., the electrical performance of the spline-shaped dual-band light wall horn 6 in the working frequency band is kept consistent, and finally the feed horn diameter is 94mm, the longitudinal dimension is 300mm, K The lowest frequency band efficiency is 70.5%, and the lowest Ka frequency band efficiency is 60.0%. As shown in Figure 7, the simulation curve of the feed pattern of the spline-shaped dual-band light-wall horn of the present invention is shown. The main lobe of the low-frequency transmitting pattern of the feed source and the first side lobe of the high-frequency receiving pattern irradiate the reflector, so that the effective electrical dimensions of the reflectors in the transmitting and receiving frequency bands are equivalent, so that the uplink and downlink patterns of the antenna have equal beam widths, such as FIG. 5 is a schematic diagram of the reflection surface irradiated by the receiving beam of the feed source according to the present invention. As shown in Figure 8, it is the simulation curve of the secondary pattern of the side-fed biased Cassegrain antenna of the present invention. From Figure 8, it can be seen that the main lobes of the uplink and downlink patterns of the antenna basically overlap, that is, they have equal beam widths, and the uplink and downlink side lobes The average level is better than 25dB.

Figure 6 is a schematic diagram of the antenna coverage area of the present invention. In order to expand the communication capacity and reduce co-channel interference, four-color multiplexing is used in the coverage area, and 40 beams are used to realize seamless coverage of the antenna coverage area. Due to the large coverage area of the antenna, the lateral focus of the feed corresponding to the edge beam is large, resulting in distortion of the edge beam, making it impossible to achieve seamless coverage at the edge of the coverage area, thereby affecting the performance of the entire antenna. In order to solve this problem, the present invention adopts a simple and effective measure: adjust the spline shaped light wall horn feed source 5 in the focal plane, and direct the spline shaped light wall horn feed source 5 to the center of the equivalent reflection surface, as Fig. 9 is a schematic diagram of the feed point of the spline shaped light wall horn of the present invention.

As shown in Figure 10a, it is a simulation curve of the K-band defocus characteristic of the side-fed biased Cassegrain antenna of the present invention, and Figure 10b is a simulation curve of the Ka-band defocus characteristic of the side-fed biased Cassegrain antenna of the present invention , Figure 10 shows the pattern scanning situation before and after the feed source adjustment, and the edge beam is consistent with the center beam pattern after adjustment.

As shown in Figure 11, it is the C/I characteristic simulation curve of the side-fed biased Cassegrain antenna of the present invention, wherein Figures 11a, 11b, 11c, and 11d respectively provide the four standards of the present invention A, B, C, and D The C/I (carrier-to-interference ratio) characteristic simulation curve of the side-fed biased Cassegrain antenna 1 can be seen from the figure that the C/I is better than 14dB.

Under the design schematic diagram of the present invention:

The side-fed biased Cassegrain antenna has a compact structure, and the increase in the size of the secondary surface and the feed source has little effect on the overall size of the antenna system. Under the premise of the same radiation gain and structural size, it has a large focal-diameter ratio, so It has the advantages of low sidelobe and cross-polarization levels, and less influence on electrical performance after the feed is defocused. According to the requirements of the satellite platform on the envelope size of the antenna, the present invention uses a standard side-feed biased Cassegrain antenna, and designs a multi-beam antenna shared by four calibers for transmitting and receiving. The feed source uses a spline-shaped dual-band light wall horn. This type of feed source has the advantages of good symmetry, low cross-polarization level, etc., and also has the advantages of good processing consistency. By optimizing the spline function, adjusting the spline control point and other means, the electrical performance of the feed speaker in each 1.6GHz working frequency band of the Ka/K transmitting and receiving frequency bands is kept consistent. By optimizing the feed horn, the main lobe of the low-frequency transmission pattern and the first side lobe of the high-frequency reception pattern illuminate the reflector, even if the effective electrical size of the reflection surface in the transceiver frequency band is equivalent, so that the antenna transceiver pattern has the same beam width. By adjusting the feed horn in the focal plane so that it points to the center of the equivalent reflector, the equalization of the edge beam and the center beam of the coverage area is realized.

The present invention creatively uses the main lobe of the low-frequency transmitting pattern of the feed source and the first side lobe of the high-frequency receiving pattern to illuminate the reflector, so that the transmitting and receiving patterns of the antenna have equal beam widths, realize the sharing of transmitting and receiving, and use the standard reflector at the same time The reflector avoids the design of the common antenna for transmitting and receiving, the design of the dichroic material and the design of the stepped circular reflector that are difficult to process and have high technical risks.

The invention solves the problem of equalization of transmitting and receiving beams, high gain of low sidelobe and maintenance of electrical performance of the antenna after defocusing, and can be applied to Ka-band transmitting and receiving shared antennas, multi-aperture multi-beam antennas, single-aperture multi-beam antennas, wide-angle scanning antennas, etc. field. Based on the characteristics of its own scheme, the antenna has the advantages of simple principle and excellent performance. It has strong practicability and market competitiveness in high-performance broadband communication satellites, broadband multimedia satellites and wide-angle scanning reconnaissance satellites.

The above description is only the best specific implementation mode of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of changes or modifications within the technical scope disclosed in the present invention. Replacement should be covered within the protection scope of the present invention.

The content that is not described in detail in the description of the present invention belongs to the well-known technology of those skilled in the art.

Claims (7)

1. A dual-band beam equalization side-fed offset Cassegrain antenna is characterized in that: it comprises four standard side-fed offset Cassegrain antennas (1) distributed on satellites, each standard side-fed The offset Cassegrain antenna (1) includes a main reflector (2), a sub-reflector (3), a feed assembly (4), a first deployment mechanism (11) and a second deployment mechanism (12), wherein the main The reflector (2) is connected with the secondary reflector (3) through the second deployment mechanism (12), the main reflector (2) is connected on the satellite through the first deployment mechanism (11), and the feed source assembly ( 4) Contains n spline-shaped light-wall horn feeds (5), each spline-shaped light-wall horn feed (5) points to the sub-reflector (3), and each spline-shaped light-wall horn feeds The phase center of the source (5) is placed on the focal plane of the standard side-fed biased Cassegrain antenna (1), and points to the center of the equivalent reflector, and each spline shaped light wall horn feed (5) is composed of a sample The strip-shaped light wall horn (6), the square-circle transition (7), the circular polarizer (8), the square-square transition (9) and the orthogonal mode coupler (10) are sequentially connected to form, and the spline shaped light wall The first sidelobe of the Ka-band pattern of the horn (6) and the main lobe of the K-band pattern -12～-15dB are all located at the feed source irradiation angle θ _a of the standard side-fed biased Cassegrain antenna (1), where n is a positive integer, n≥8. 2. A dual-band beam equalization side-fed bias Cassegrain antenna according to claim 1, characterized in that: the spline-shaped light wall horn (6) is jammed according to the standard side-fed bias The feed illumination angle θ _a of the Glenn antenna (1) and the maximum aperture D _f of the spline-shaped light-wall horn feed (5) are designed, and the maximum diameter of the spline-shaped light-wall horn feed (5) Caliber D _f is calculated according to satellite communication coverage area and four-color multiplexing planning. 3. A kind of dual-band beam equalization side-fed biased Cassegrain antenna according to claim 1, characterized in that: in the Ka frequency band 1.6GHz operating frequency band of the spline shaped light wall horn (6) Both the first side lobe of the pattern and the main lobe -12--15dB of the pattern in the K-band 1.6GHz operating frequency band are located at the feed source irradiation angle _{θ a} of the standard side-fed biased Cassegrain antenna (1). 4. A kind of dual-band beam equalization side-fed offset Cassegrain antenna according to claim 1, characterized in that: the feeders in the four standard side-fed offset Cassegrain antennas (1) The number of spline shaped light wall horn feed sources (5) included in the source component (4) may be the same or different. 5. A method for realizing a dual-band beam equalization side-fed biased Cassegrain antenna, characterized in that: comprising the steps: Step 1: Design four standard side-fed biased Cassegrain antennas (1) according to the antenna size required by the satellite platform, and obtain the feed irradiation angle θ _a ; Step 2: Calculate the maximum aperture D _f of the feed source according to the satellite communication coverage area and the four-color multiplexing plan; Step 3: According to the feed irradiation angle θ _a of the standard side-fed biased Cassegrain antenna (1) obtained in the first step and the feed diameter D _f obtained in the second step, design the spline shaped light wall horn (6), the first side lobe of the Ka frequency band pattern and the K frequency band pattern main lobe-12～-15dB of the spline shaped light wall horn (6) are all located at the θ _a place; The fourth step: combine the spline-shaped light wall horn (6) obtained in the third step with the square-circle transition (7), circular polarizer (8), square-square transition (9) and orthogonal mode coupler (10) connected sequentially to obtain a spline-shaped light-wall horn feed (5), n spline-shaped light-wall horn feeds (5) form a feed assembly (4), and a total of four feed assemblies (4) are formed , where n is a positive integer, n≥8 Step 5: Install the feed assembly (4) obtained in step 4 into the standard side-fed offset Cassegrain antenna (1) obtained in the first step, each standard side-fed offset Cassegrain antenna (1) Install a feed source assembly (4), and make the phase center of each spline-shaped light wall horn feed source (5) be placed in the focal plane of the standard side-fed offset Cassegrain antenna (1), and Point to the center of the equivalent reflective surface. 6. the realization method of a kind of dual-band beam equalization side-fed bias Cassegrain antenna according to claim 5, is characterized in that: in the described 3rd step, the spline shaped light wall horn (6) The first side lobe of the Ka-band 1.6GHz working frequency band pattern and the main lobe -12～-15dB of the K-band 1.6GHz working frequency band pattern are located at the feed source irradiation angle of the standard side-fed biased Cassegrain antenna (1) _θa . 7. the realization method of a kind of dual-band beam equalization side-fed offset Cassegrain antenna according to claim 5, it is characterized in that: the four feed source components (4) included in the fourth step The number of spline shaped light wall horn feed sources (5) may be the same or different.

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