Multi-band high-gain reflector antenna based on frequency selective surface subreflector

Abstract

The invention relates to the technical field of microwave devices, and provides a multi-band high-gain reflector antenna based on a frequency selective surface secondary reflector, which comprises a main reflector, a secondary reflector with a frequency selective surface, a secondary reflector support rod and a feed source device, the auxiliary reflecting surface is fixedly connected with the main reflecting surface through a plurality of auxiliary reverse supporting rods; the auxiliary reflecting surface is formed by integrally processing a central rotating elliptical surface and an annular frequency selective surface; the feed source device is arranged in a rear focal region of the auxiliary reflecting surface; the SC broadband feed source array is connected with the radio frequency signal input end through the broadband SC synthesis network and is used for broadband radiation of an S / C frequency band; the Ku / K / EHF feed source system is connected with the radio frequency signal input end through the multi-frequency waveguide network and is used for transmitting and receiving Ku, K and EHF frequency band signals. A frequency selective surface structure is introduced to the edge of the sub-reflecting surface, and a nested Ku / K / EHF multi-frequency feed source system and an orthogonal polarization layout are combined, so that multi-band co-feed, high-efficiency radiation and compact structure design is realized, and the antenna is particularly suitable for satellite communication with compact space.

Description

Technical Field

[0001] This invention relates to the field of microwave device technology, and in particular to a multi-band high-gain reflector antenna based on a frequency-selective surface sub-reflector, suitable for communication antennas in the SC, Ku, K and EHF bands for high-orbit satellite transmission. Background Technology

[0002] Reflector antennas are widely used in satellite communications due to their high efficiency, simple structure, and high reliability. However, with the expansion of communication frequencies to higher frequency bands such as Ku, K and EHF, and the rapid development of miniaturized satellite platforms, the traditional reflector antenna structure has gradually revealed its limitations in terms of compactness, frequency band compatibility, and radiation efficiency, making it difficult to simultaneously meet the engineering requirements of multi-band sharing and miniaturized integration.

[0003] Traditional reflector antennas typically rely on the radiation characteristics and taper angle design of the feed to achieve high-efficiency illumination of the main reflector. When operating in the low-frequency band, to ensure illumination uniformity and aperture illumination efficiency, the feed aperture size needs to be increased accordingly, resulting in a significant increase in the focal zone space occupied. This makes arrangement within the limited reflector structure area difficult and prone to electromagnetic obstruction and installation interference problems. For reflectors operating in multiple frequency bands, the feed must simultaneously meet the beam taper, impedance matching, and phase requirements of different frequency bands, resulting in complex structural designs and difficulty in maintaining high-efficiency radiation performance across all frequency bands. When the reflector aperture is large, the feed area size and space can be increased to accommodate multi-frequency feed networks. However, under constraints such as miniaturized satellite platforms, the reflector aperture is limited by the platform size, making it difficult to integrate large-aperture feeds with multi-channel feed networks. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a multi-band high-gain reflector antenna based on a frequency-selective surface sub-reflector. By adding a frequency-selective surface to the edge of the sub-reflector, the sub-reflector size is effectively increased, thereby increasing primary reflection of the low-frequency portion of the composite feed, reducing the tapering requirements of the low-frequency feed, and decreasing the size of the low-frequency feed. Simultaneously, the frequency-selective surface allows high-frequency electromagnetic waves to pass through, reducing the impact on high-frequency radiation. By designing a nested network that nests the Ku, K, and EHF bands, the feed network size is reduced, facilitating layout in smaller apertures. Furthermore, polarization diversity reduces coupling between frequency bands, saving on isolation network design and achieving a compact design for the small-aperture reflector. To achieve the above-mentioned objectives, this invention adopts the following technical solution: This invention provides a multi-band high-gain reflector antenna based on a frequency-selective surface subreflector, comprising: a main reflector, a subreflector with a frequency-selective surface, a subreflector support rod, and a feed device; wherein, The secondary reflector is fixedly connected to the primary reflector by several secondary anti-support rods; the secondary reflector is integrally formed by a central rotating elliptical surface and an annular frequency selective surface. The rotating elliptical surface is used to reflect high and low frequency electromagnetic waves, and the annular frequency selective surface is used to reflect low frequency electromagnetic waves without affecting the transmission of high frequency electromagnetic waves. The feed device is located in the rear focal region of the sub-reflector and is used to emit electromagnetic waves into the sub-reflector. After being reflected or transmitted by the sub-reflector to the main reflector, the waves are converged by the main reflector and radiated in the direction in front of the antenna. The feed device includes an SC broadband feed array, a broadband SC combining network, and a Ku / K / EHF feed system. The SC broadband feed array is connected to the radio frequency signal input terminal through the broadband SC combining network and is used for broadband radiation in the S / C band. The Ku / K / EHF feed system is connected to the radio frequency signal input terminal through a multi-frequency waveguide network and is used for the transmission and reception of Ku, K, and EHF band signals.

[0005] Furthermore, the main reflector is a parabolic rotating surface structure, with its reflective surface facing the sub-reflector. It is used to receive electromagnetic waves reflected by the sub-reflector and then converge them to radiate along the direction in front of the antenna.

[0006] Furthermore, the sub-reflector is made of metal, and the annular frequency selection surface and the rotating elliptical surface are arranged coaxially, forming a stepped transition structure at the connection point. The transition height difference is u, where u is a positive real number greater than zero. The ring frequency selective surface is a planar ring structure. The inner edge of the ring frequency selective surface is connected to the outer edge of the rotating elliptical surface, and the outer edge of the ring frequency selective surface is the outer edge of the sub-reflecting surface. The middle of the ring frequency selective surface is provided with two rows of periodic through holes distributed at equal intervals along the ring direction.

[0007] Furthermore, the main body of the secondary reflector support rod is an elliptical cross-section rod structure made of carbon fiber material, and titanium alloy joints are provided at both ends. The titanium alloy joints are used to fix the secondary reflector support rod to the main reflector and the secondary reflector respectively.

[0008] Furthermore, the SC broadband feed array consists of two SC elements, which are broadband ridge waveguide shaped horn antennas arranged on both sides of the Ku / K / EHF feed system. Together with the Ku / K / EHF feed system, they are located at the focal point of the reflector and are connected to the broadband SC synthesis network through two high-frequency cables.

[0009] Furthermore, the waveguide end of the broadband ridge waveguide shaped horn antenna is located at the bottom and connected to the broadband SC synthesizer network, while the horn mouth is located at the top and arranged towards the sub-reflector. The broadband ridge waveguide shaped horn antenna is an axisymmetric conical structure that expands in length from the waveguide end to the horn mouth. It has a mutually symmetrical double ridge structure inside for broadband matching of the S / C band.

[0010] Furthermore, the Ku / K / EHF feed system includes a Ku / K / EHF broadband feed, a Ku coupling network, a K coupling network, and an EHF network. The Ku / K / EHF broadband feed is a multi-frequency shared waveguide structure used to achieve co-feed transmission of Ku, K, and EHF band signals within the main feed channel.

[0011] Furthermore, in the Ku / K / EHF feed system, The Ku-coupled network consists of a set of Ku broadband couplers, two Ku filter components, and a Ku-band broadband synthesizer connected in sequence. It is arranged in a gate-shaped structure and placed parallel to the SC array, along the Y-axis of the feed coordinate system. The waveguide outlet direction is parallel to the X-axis of the feed coordinate system, and it is a horizontally polarized wave. The K-coupled network contains K-wideband coupling devices and K-wideband synthesizers connected sequentially by waveguides. It has a gate-shaped structure and is arranged orthogonally to the Ku-coupled network. It is placed perpendicular to the SC array and along the X-axis of the feed coordinate system. The waveguide outlet is arranged along the Y-axis of the feed coordinate system, and it is a vertically polarized wave. The EHF network is located at the lower end of the main feed channel and is coaxially connected to the main feed channel via a waveguide flange. The EHF network is a waveguide transformation section structure, which transforms from a circular waveguide to a BJ400 standard rectangular waveguide port. The waveguide outlet direction is along the X-axis of the feed coordinate system and is a horizontally polarized wave.

[0012] Furthermore, the Ku / K / EHF broadband feed is a multimode horn structure, comprising a tapered circular waveguide section, a straight waveguide section, and a tapered circular horn section connected in sequence, and the phase center of the Ku / K / EHF broadband feed is located at the focal point of the reflector axis. Furthermore, the Ku-coupled network is orthogonally arranged with the K-network and is located at the axial front end of the Ku / K / EHF feed broadband feed, while the K-coupled network is located at the axial rear end of the Ku / K / EHF feed broadband feed.

[0013] Compared with the prior art, the present invention has at least one of the following technical advantages: By introducing a frequency-selective surface structure at the edge of the sub-reflector and combining it with a nested Ku / K / EHF multi-frequency feed system and orthogonal polarization layout, a multi-band co-feed, high-efficiency radiation, and compact design were achieved. The frequency-selective surface reflects low-frequency electromagnetic waves and transmits high-frequency signals, increasing the equivalent aperture of the sub-reflector and improving the radiation efficiency in the S / C band without affecting high-frequency performance. The nested feed structure effectively reduces the feed grid size and isolation network complexity through coaxial co-feeding and polarization separation of the Ku, K, and EHF bands. Combined with the design of a broadband ridge waveguide shaped horn array, the antenna can still achieve multi-frequency sharing and high-gain output from S / C to EHF with an aperture of less than 0.9m. Experimental results show that the S / C band efficiency reaches 30%–40%, and the high-frequency band (Ku, K, EHF) efficiency is approximately 55%, significantly better than the 10%–20% low-frequency efficiency of traditional composite reflector antennas, demonstrating the comprehensive advantages of compact structure, frequency band compatibility, and high radiation efficiency. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below: Figure 1 This is a structural diagram of the multi-band high-gain reflector antenna of the present invention; Figure 2 This is a detailed structural diagram of the frequency-selective surface sub-reflector in an embodiment of the present invention; Figure 3 This is a structural diagram of the SC broadband feed array in an embodiment of the present invention; Figure 4 This is a structural diagram of the Ku / K / EHF feed system in an embodiment of the present invention; Figure 5 This is the measured radiation pattern of the S-band gain in an embodiment of the present invention; Figure 6 This is the measured radiation pattern of the C-band gain in an embodiment of the present invention; Figure 7 This is a measured radiation pattern of Ku-band gain in an embodiment of the present invention; Figure 8 This is a measured radiation pattern of the K-band gain in an embodiment of the present invention; Figure 9 This is a measured radiation pattern of the EHF band gain in an embodiment of the present invention.

[0015] Figure Labels 1: Main reflector; 2: Sub-reflector; 2-1: Rotating elliptical surface; 2-2: Annular frequency selective surface; 3: Sub-reflector support rod; 4: SC broadband feed array; 4-1: Double ridge structure; 5: Broadband SC synthesizer network; 6: Ku / K / EHF feed system; 6-1: Ku / K / EHF broadband feed; 6-2: Ku coupling network; 6-2-1: Ku broadband coupler; 6-2-2: Ku filter assembly; 6-3: K coupling network; 6-3-1: K broadband coupler; 6-3-2: K broadband synthesizer assembly; 6-4: EHF network. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0017] First Embodiment This invention provides a multi-band high-gain reflector antenna based on a frequency-selective surface sub-reflector, such as... Figure 1 As shown, it includes: a main reflector, a sub-reflector with a frequency-selective surface, a sub-reflector support rod, and a feed device; wherein, The secondary reflector is fixedly connected to the primary reflector by several secondary anti-support rods; the secondary reflector is integrally formed by a central rotating elliptical surface and an annular frequency selective surface. The rotating elliptical surface is used to reflect high and low frequency electromagnetic waves, and the annular frequency selective surface is used to reflect low frequency electromagnetic waves without affecting the transmission of high frequency electromagnetic waves. The feed device is located in the rear focal region of the sub-reflector and is used to emit electromagnetic waves into the sub-reflector. After being reflected or transmitted by the sub-reflector to the main reflector, the waves are converged by the main reflector and radiated in the direction in front of the antenna. The feed device includes an SC broadband feed array, a broadband SC combining network, and a Ku / K / EHF feed system. The SC broadband feed array is connected to the radio frequency signal input terminal through the broadband SC combining network and is used for broadband radiation in the S / C band. The Ku / K / EHF feed system is connected to the radio frequency signal input terminal through a multi-frequency waveguide network and is used for the transmission and reception of Ku, K, and EHF band signals.

[0018] Furthermore, the main reflector is a parabolic rotating surface structure, with its reflective surface facing the sub-reflector. It is used to receive electromagnetic waves reflected by the sub-reflector and then converge them to radiate along the direction in front of the antenna.

[0019] Specifically, such as Figure 1As shown, the multi-band high-gain reflector antenna based on a frequency-selective surface sub-reflector provided by the present invention mainly includes: a main reflector (1), a sub-reflector with a frequency-selective surface (2), a sub-reflector support rod (3), an SC broadband feed array (4), a broadband SC synthesis network (5), and a Ku / K / EHF feed system (6). Among them, the main reflector (1) adopts a parabolic rotation structure, and its reflector is arranged facing the sub-reflector to receive electromagnetic waves emitted from the feed device and reflected or transmitted by the sub-reflector; the diameter of the main reflector is d_main_reflector = 900 mm, the focal length is f = 240 mm, the focal diameter ratio is moderate, and it can take into account both high-frequency beam focusing and low-frequency illumination efficiency.

[0020] The sub-reflector (2) is fixedly connected to the main reflector (1) by several sub-reflector support rods (3) and is arranged as a whole in front of the focal area of ​​the main reflector. The sub-reflector is formed by integrally processing a central rotating elliptical surface and a ring frequency selective surface. The rotating elliptical surface is mainly used for the reflection of high and low frequency electromagnetic waves, and the ring frequency selective surface is used to achieve electromagnetic selective separation of low frequency reflection and high frequency transmission. The feed device is located at the center of the focal area behind the sub-reflector and includes SC broadband feed arrays (4) on both sides and a Ku / K / EHF feed system (6) in the middle. The two are connected to the radio frequency signal input end through a broadband SC synthesis network (5). The SC broadband feed array (4) is used for broadband radiation in the S / C band, and the Ku / K / EHF feed system (6) is used for co-feed transmission and reception of Ku, K and EHF band signals. Through the above structural layout, the main and sub-reflectors and the feed system form a compact and efficient electromagnetic coupling in the focal area, realizing multi-band sharing and high-gain output.

[0021] Furthermore, the sub-reflector is made of metal, and the annular frequency selection surface and the rotating elliptical surface are arranged coaxially, forming a stepped transition structure at the connection point. The transition height difference is u, where u is a positive real number greater than zero. The ring frequency selective surface is a planar ring structure. The inner edge of the ring frequency selective surface is connected to the outer edge of the rotating elliptical surface, and the outer edge of the ring frequency selective surface is the outer edge of the sub-reflecting surface. The middle of the ring frequency selective surface is provided with two rows of periodic through holes distributed at equal intervals along the ring direction.

[0022] Specifically, such as Figure 2 As shown, Figure 2This is a detailed structural diagram of the sub-reflector (2). Specifically, the sub-reflector is integrally formed by a central rotating elliptical surface and an annular frequency selective surface. The rotating elliptical surface (2-1) is a three-dimensional curved surface generated by rotating an ellipse around the axis of the sub-reflector. Its equivalent aperture diameter is dellipse = 100 mm, which is used to realize the reflection and wavefront shaping of high and low frequency electromagnetic waves. The annular frequency selective surface (2-2) is a planar annular structure. Its inner diameter is connected to the edge of the rotating elliptical surface, i.e., dinner diameter = 100 mm, and its outer diameter is dsubreflector = 200 mm. Two rows of periodic through-hole arrays are uniformly distributed along the circumference in the middle, which are used to realize low frequency reflection and high frequency transmission. The inner row has 16 through holes, evenly spaced at 22.5° intervals, with the center of each hole located on an arc with a diameter of d_inner_row = 124 mm. The outer row has 20 through holes, evenly spaced at 18° intervals, with the center of each hole located on an arc with a diameter of d_outer_row = 168 mm. These two rows of through holes together form a ring-shaped frequency selective array. To improve electromagnetic coupling performance and enhance the phase uniformity of the high-frequency transmitted wave, the ring-shaped frequency selective surface (2-2) is raised by a height difference u = 5 mm relative to the rotating elliptical surface (2-1) along the axis of the sub-reflector, forming a stepped transition structure that achieves dual optimization of mechanical stability and electromagnetic response.

[0023] Furthermore, the main body of the secondary reflector support rod is an elliptical cross-section rod structure made of carbon fiber material, and titanium alloy joints are provided at both ends. The titanium alloy joints are used to fix the secondary reflector support rod to the main reflector and the secondary reflector respectively.

[0024] Furthermore, the SC broadband feed array consists of two SC elements, which are broadband ridge waveguide shaped horn antennas arranged on both sides of the Ku / K / EHF feed system. Together with the Ku / K / EHF feed system, they are located at the focal point of the reflector and are connected to the broadband SC synthesis network through two high-frequency cables.

[0025] Furthermore, the waveguide end of the broadband ridge waveguide shaped horn antenna is located at the bottom and connected to the broadband SC synthesizer network, while the horn mouth is located at the top and arranged towards the sub-reflector. The broadband ridge waveguide shaped horn antenna is an axisymmetric conical structure that expands in length from the waveguide end to the horn mouth. It has a mutually symmetrical double ridge structure inside for broadband matching of the S / C band.

[0026] Specifically, such as Figure 3As shown, the SC broadband feed array (4) consists of two SC elements, which are respectively arranged on both sides of the Ku / K / EHF feed system. All three are located at the focal point of the main reflector, and are used to realize broadband radiation and reception in the S / C band. Each of the SC elements adopts a broadband ridge waveguide shaped horn antenna (4-1) structure. The waveguide end of the broadband ridge waveguide shaped horn antenna (4-1) is located at the bottom and is electrically connected to the broadband SC synthesizer network through the waveguide interface; its horn mouth is located at the top and is arranged towards the sub-reflector. The horn antenna as a whole has an axisymmetric conical structure, and its length gradually expands from the waveguide end to the horn mouth. Two mutually symmetrical ridge structures are set inside to form a stable TEM and TE mixed mode transmission, realizing broadband impedance matching and high-gain radiation in the S / C band. Among them, the lower opening size of the horn antenna is I_bottom, the upper opening size is I_top, and the height is h. The ridge structure gradually unfolds along the waveguide axis to achieve good mode conversion and radiation directivity. The antenna waveguide end is connected to the broadband SC synthesis network (5) through a high-frequency cable to realize the synthesis and feeding of multi-element signals.

[0027] Furthermore, such as Figure 4 As shown, the Ku / K / EHF feed system includes a Ku / K / EHF broadband feed, a Ku coupling network, a K coupling network, and an EHF network. The Ku / K / EHF broadband feed is a multi-frequency shared waveguide structure used to achieve co-feed transmission of Ku, K, and EHF band signals within the main feed channel.

[0028] Furthermore, in the Ku / K / EHF feed system, The Ku-coupled network consists of a set of Ku broadband couplers, two Ku filter components, and a Ku-band broadband synthesizer connected in sequence. It is arranged in a gate-shaped structure and placed parallel to the SC array, along the Y-axis of the feed coordinate system. The waveguide outlet direction is parallel to the X-axis of the feed coordinate system, and it is a horizontally polarized wave. The K-coupled network contains K-wideband coupling devices and K-wideband synthesizers connected sequentially by waveguides. It has a gate-shaped structure and is arranged orthogonally to the Ku-coupled network. It is placed perpendicular to the SC array and along the X-axis of the feed coordinate system. The waveguide outlet is arranged along the Y-axis of the feed coordinate system, and it is a vertically polarized wave. The EHF network is located at the lower end of the main feed channel and is coaxially connected to the main feed channel via a waveguide flange. The EHF network is a waveguide transformation section structure, which transforms from a circular waveguide to a BJ400 standard rectangular waveguide port. The waveguide outlet direction is along the X-axis of the feed coordinate system and is a horizontally polarized wave.

[0029] Furthermore, the Ku / K / EHF broadband feed is a multimode horn structure, comprising a tapered circular waveguide section, a straight waveguide section, and a tapered circular horn section connected in sequence, and the phase center of the Ku / K / EHF broadband feed is located at the focal point of the reflector axis. Furthermore, the Ku-coupled network is orthogonally arranged with the K-network and is located at the axial front end of the Ku / K / EHF feed broadband feed, while the K-coupled network is located at the axial rear end of the Ku / K / EHF feed broadband feed.

[0030] Specifically, such as Figure 5-9 As can be seen from the experimental results of the frequency-selective surface-mounted compact high-gain multi-band reflector antenna of the present invention, the present invention can generate high gain in five separate frequency bands: S, C, Ku, K, and EHF (SC band: 2~7GHz; Ku band: 12~14GHz; K band: 17~22GHz; EHF: 40~46GHz). The antenna achieves an axial gain of 22 and an efficiency of 40% in the S band; 32 and an efficiency of 50% in the C band; 39 and an efficiency of 55% in the Ku band; 41.8 and an efficiency of 55% in the K band; and 51 and an efficiency of 65% in the EHF band. Analysis of the high-frequency gain shows that the frequency-selective surface only plays a positive role in improving the efficiency of the low-frequency band and does not affect the high-frequency gain, thus achieving high-efficiency operation across multiple frequency bands, including the low-frequency band.

[0031] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A multi-band high-gain reflector antenna based on a frequency-selective surface sub-reflector, characterized in that, include: The system includes a main reflector, a sub-reflector with a frequency-selective surface, a sub-reflector support rod, and a feed device; among which, The secondary reflector is fixedly connected to the primary reflector via several secondary reflector support rods; the secondary reflector is integrally formed by a central rotating elliptical surface and an annular frequency selective surface, the rotating elliptical surface is used to reflect high and low frequency electromagnetic waves, and the annular frequency selective surface is used to reflect low frequency electromagnetic waves without affecting the transmission of high frequency electromagnetic waves. The feed device is arranged in the rear focal region of the sub-reflector and is used to emit the electromagnetic waves toward the sub-reflector. After being reflected or transmitted by the sub-reflector to the main reflector, the waves are converged by the main reflector and radiated along the direction in front of the antenna. The feed device includes an SC broadband feed array, a broadband SC combining network, and a Ku / K / EHF feed system. The SC broadband feed array is connected to the radio frequency signal input terminal through the broadband SC combining network and is used for broadband radiation in the S / C band. The Ku / K / EHF feed system is connected to the radio frequency signal input terminal through a multi-frequency waveguide network and is used for the transmission and reception of Ku, K, and EHF band signals.

2. The multi-band high-gain reflector antenna according to claim 1, characterized in that, The main reflector is a parabolic rotating surface structure, with its reflective surface facing the sub-reflector. It is used to receive the electromagnetic waves reflected by the sub-reflector and then converge them to radiate along the front direction of the antenna.

3. The multi-band high-gain reflector antenna according to claim 1, characterized in that, The sub-reflector is made of metal. The annular frequency-selective surface and the rotating elliptical surface are coaxially arranged and form a stepped transition structure at the connection point. The transition height difference is u, where u is a positive real number greater than zero. The annular frequency selective surface is a planar annular structure. The inner edge of the annular frequency selective surface is connected to the outer edge of the rotating elliptical surface, and the outer edge of the annular frequency selective surface is the outer edge of the sub-reflecting surface. The annular frequency selective surface has two rows of periodic through-hole arrays evenly distributed along the circumferential direction in the middle.

4. The multi-band high-gain reflector antenna according to claim 1, characterized in that, The main body of the secondary reflector support rod is an elliptical cross-section rod structure made of carbon fiber material, and titanium alloy joints are provided at both ends. The titanium alloy joints are used to fix the secondary reflector support rod to the main reflector and the secondary reflector respectively.

5. The multi-band high-gain reflector antenna according to claim 1, characterized in that, The SC broadband feed array consists of two SC elements, each of which is a broadband ridge waveguide shaped horn antenna. These elements are arranged on both sides of the Ku / K / EHF feed system and are located at the focal point of the reflector together with the Ku / K / EHF feed system. They are connected to the broadband SC combining network via two high-frequency cables.

6. The multi-band high-gain reflector antenna according to claim 5, characterized in that, The waveguide end of the broadband ridge waveguide shaped horn antenna is located at the bottom and connected to the broadband SC synthesizing network, while the horn mouth is located at the top and arranged towards the sub-reflector. The broadband ridge waveguide shaped horn antenna is an axisymmetric conical structure that expands in length from the waveguide end to the horn mouth. It has a mutually symmetrical double ridge structure inside for broadband matching of the S / C band.

7. The multi-band high-gain reflector antenna according to claim 6, characterized in that, The Ku / K / EHF feed system includes a Ku / K / EHF broadband feed, a Ku coupling network, a K coupling network, and an EHF network. The Ku / K / EHF broadband feed is a multi-frequency shared waveguide structure used to realize the co-feed transmission of the Ku, K, and EHF frequency band signals within the main feed channel.

8. The multi-band high-gain reflector antenna according to claim 7, characterized in that, In the Ku / K / EHF feed system, The Ku coupling network consists of a set of Ku broadband coupling devices, two Ku filter components and a Ku band broadband synthesis component connected in sequence. It is arranged in a gate-shaped structure and placed parallel to the SC array, along the Y-axis of the feed coordinate system, and the waveguide outlet direction is parallel to the X-axis of the feed coordinate system, which is a horizontally polarized wave. The K-coupled network includes K-wideband coupling devices and K-wideband synthesizing components connected sequentially by waveguides, forming a gate-shaped structure and arranged orthogonally to the Ku-coupled network. It is placed perpendicular to the SC array and along the X-axis of the feed coordinate system. The waveguide outlet direction is arranged along the Y-axis of the feed coordinate system, and it is a vertically polarized wave. The EHF network is located at the lower end of the main feed channel and is coaxially connected to the main feed channel via a waveguide flange. The EHF network is a waveguide transformation section structure, which transforms a circular waveguide into a BJ400 standard rectangular waveguide port. The waveguide outlet direction is along the X-axis of the feed coordinate system and is the horizontally polarized wave.

9. The multi-band high-gain reflector antenna according to claim 8, characterized in that, The Ku / K / EHF broadband feed is a multimode horn structure, comprising a tapered circular waveguide section, a straight waveguide section, and a tapered circular horn section connected in sequence, and the phase center of the Ku / K / EHF broadband feed is located at the focal point of the axis of the reflecting surface.

10. The multi-band high-gain reflector antenna according to claim 9, characterized in that, The Ku-coupled network is orthogonally arranged to the K-network and is located at the axial front end of the Ku / K / EHF feed broadband feed, while the K-coupled network is located at the axial rear end of the Ku / K / EHF feed broadband feed.

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