A dual-band, ultra-wideband, multi-beam, dual-polarized positive feed reflector antenna

Abstract

The application discloses a kind of dual-band, ultra-wideband, multi-beam, dual-polarized positive feed reflector antenna, it is related to antenna technical technical field, including positive feed single reflector and dual-band feed source array, dual-band feed source array is longitudinally defocused to positive feed single reflector direction, and the main beam of each feed source on feed source array is directed to positive feed single reflector direction;Including high-frequency band feed source subarray and low-frequency band feed source subarray, each feed source in high-frequency band feed source subarray and low-frequency band feed source subarray is focused into narrow beam by positive feed single reflector, and each feed source is polarized into dual circular polarization after focusing by positive feed single reflector;Variable opening angle logarithmic periodic antenna is used in high-frequency band feed source subarray and low-frequency band feed source subarray, with the advantages of small size, low profile, high gain etc.;Wherein, the multi-beam antenna formed, under the same coverage area, single beam coverage area is large, and the number of required beams is less, and the coverage difference between different frequencies of each subarray is small.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, specifically to a dual-band, ultra-wideband, multi-beam, dual-polarized positive feedforward reflector antenna. Background Technology

[0002] Spectrum detection satellites are a crucial component of the aerospace technology frequency management center system. Their primary signal receivers include satellite communication uplink signals, various ground communication signals, and abnormal telemetry and control signals. These signals are then received, identified, demodulated, and sorted. To detect all of these signals, the antenna bandwidth must be at least ten times the frequency, and it must also possess high gain and wide coverage. Because of their high orbits, wide ground coverage, and good timeliness, these satellites can continuously monitor and track enemy radar and communication systems over large areas for extended periods, regardless of geographical location or weather conditions. Therefore, they have attracted significant attention from major spacefaring nations. Multi-beam reflector antennas are a common solution for achieving high gain and wide spatial coverage. They transform the large-area coverage of a single beam into coverage of multiple smaller areas by multiple narrow beams. Ultra-wideband, multi-beam single-reflector antennas require minimal difference in the combined coverage area across the entire frequency band. However, according to antenna principles, the main problems faced by dual-band, ultra-wideband multi-beam single-reflector antenna feed arrays are: the ratio of the highest to the lowest frequency in each band of a dual-band, ultra-wideband single-reflector antenna is approximately 3.5 harmonics; when the two bands are combined, the highest frequency is more than ten times the lowest. According to the aperture antenna gain formula: in This represents the gain of the equivalent aperture antenna. Indicates the equivalent wavelength. This represents the diameter of the parabola. This represents the radiation efficiency of the aperture antenna; from this formula, it can be seen that the gain difference between the highest and lowest frequencies exceeds 20dB, while the main lobe half-power beamwidth and wavelength of a parabolic antenna of the same aperture are... Proportional to diameter Inversely proportional, the beamwidth of the highest and lowest frequencies differs by a factor of 12, while the coverage area differs by tens or even hundreds of times. This is a common problem for both prime-fed and offset-fed single-reflector antennas.

[0003] For positive-feed ultra-wideband, multi-beam single-reflector antennas, the increasing focus leads to more pronounced beam distortion at higher frequencies, further exacerbating the beam coverage differences between high and low frequencies. For positive-feed single-reflector antennas, the feed array severely obstructs the main beam, and the degree of obstruction varies depending on the feed beam's position after focusing by the reflector. For ultra-wideband, multi-beam single-reflector antennas, to avoid significant differences in beam coverage between high and low frequencies, a common approach is to design the low-band antenna based on its center frequency. However, this approach not only requires a large number of beams and increases post-processing pressure but also fails to guarantee complete coverage across the entire frequency band. Summary of the Invention

[0004] The purpose of this invention is to provide a dual-band, ultra-wideband, multi-beam, dual-polarized positive feedforward reflector antenna that achieves wide spatial range, high gain, and lossless coverage with fewer beams.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a dual-band, ultra-wideband, multi-beam, dual-polarized positive feedforward reflector antenna, comprising:

[0006] Positive feedforward single reflector;

[0007] The dual-band feed array is configured to be longitudinally focused towards the positive feed single reflector, and the main beam of each feed on the feed array points towards the positive feed single reflector; and

[0008] The system includes a high-frequency feed subarray and a low-frequency feed subarray. Each feed in the high-frequency and low-frequency feed subarrays is focused into a narrow beam by a positive feedforward single reflector, and each feed is polarized into dual circular polarization after being focused by the positive feedforward single reflector.

[0009] Preferably, the longitudinal projected diameter of the reflecting surface is Satisfying the equation of a parabola ,in , Let x be the horizontal coordinate axis of the parabola. The vertical axis is the coordinate axis. Let be the focal length of the parabola.

[0010] Preferably, each feed in the low-frequency band feed subarray is a dual-circular polarization feed, and the feed includes a dual-linear polarization antenna and a dual-circular polarization forming network.

[0011] Preferably, the dual-polarized antenna in each feed of the low-frequency feed subarray includes a pair of complementary structure variable angle log-periodic antennas in the low-frequency band and a dielectric support in the low-frequency band, and the dual-circular polarization forming network includes a 90° hybrid bridge with corresponding frequency band functions.

[0012] Preferably, the high-frequency feed subarray is a dual-circular polarization feed, which includes a dual-linear polarization antenna and a dual-circular polarization forming network.

[0013] Preferably, the dual-polarized antenna in each feed of the high-frequency feed subarray includes a pair of complementary high-frequency structure variable-angle log-periodic antennas and a high-frequency metal reflector. A cylindrical support for the high-frequency band is located at the bottom, and the dual-circular polarization forming network includes a 90° hybrid bridge corresponding to the frequency band function.

[0014] Preferably, each feed in the low-frequency band feed subarray operates independently, and multiple narrow beams are combined to form a multi-beam array. Each beam can achieve zero-loss coverage within the designed bandwidth of the low-frequency band within a predetermined coverage gain.

[0015] Preferably, each feed in the high-frequency feed subarray operates independently, and multiple narrow beams are combined to form a multi-beam array. Each beam can achieve coverage without leakage within the high-frequency band design bandwidth within a predetermined coverage gain.

[0016] Preferably, the frequency bands of the dual-band feed array include low-frequency bands and high-frequency bands, and the bandwidths of the two frequency bands are arbitrary.

[0017] Preferably, the adjacent feeds in the low-frequency feed subarray are arranged in a triangular pattern, and the feeds in the high-frequency feed subarray are interspersed in the low-frequency feed subarray.

[0018] Preferably, the dual-band feed array further includes an arc-shaped mounting surface, with the high-frequency feed subarray and the low-frequency feed subarray mounted on the convex surface of the arc-shaped mounting surface, and the direction of each beam is orthogonal to the tangent direction of the arc-shaped mounting surface.

[0019] Beneficial effects: This invention aims to eliminate the negative impact of the feed array blocking the main beam, thereby eliminating the difference in coverage area between high and low frequency beams. It achieves a large coverage area for a single beam with a given gain, requires fewer beams for the same coverage area, and exhibits small differences in coverage area between different frequencies from the same feed source, resulting in uniform coverage and strong practicality. Furthermore, the beamwidth of each frequency band in the antenna can be designed according to performance requirements. Within the designed bandwidth, the beamwidth of each frequency band can be the same or different. Both the high-frequency and low-frequency feed subarrays employ variable-angle log-periodic antennas, which have advantages such as small size, low profile, and high gain.

[0020] In addition, the antenna performance of this invention has strong flexibility, a wider range of applications, and greater practicality, especially in terms of reflective surfaces, lenses, and corner reflectors. Attached Figure Description

[0021] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0022] In the attached diagram:

[0023] Figure 1 This is a schematic diagram of the structure of the dual-band, ultra-wideband, multi-beam, dual-polarized positive feedforward reflector antenna of the present invention;

[0024] Figure 2 This is a schematic diagram of the multi-beamforming principle of the present invention;

[0025] Figure 3 This is a schematic diagram of the dual-band feed array of the present invention;

[0026] Figure 4 This is a schematic diagram of the left and right circular polarization feed principle of the present invention;

[0027] Figure 5 This is the low-frequency band variable angle logarithmic periodic feed diagram of the present invention;

[0028] Figure 6 This is the high-frequency band variable angle logarithmic periodic feed diagram of the present invention;

[0029] Figure 7 This is a structural diagram of the variable-angle log-periodic antenna of the present invention;

[0030] Figure 8 This is a schematic diagram of the metal reflector and complementary structure logarithmic periodic oscillator support structure of the present invention;

[0031] Figure 9 This is a schematic diagram of the dual-band, ultra-wideband, dual-polarization, multi-beam feed array of the present invention;

[0032] Figure 10 This is the low-frequency band of the present invention. Multibeam coverage pattern;

[0033] Figure 11 This is the low-frequency band of the present invention. Multibeam coverage pattern;

[0034] Figure 12 The high-frequency band of this invention is... Multi-beam coverage pattern;

[0035] Figure 13 The high-frequency band of this invention is... Multi-beam coverage pattern;

[0036] The diagram is labeled as follows: 1. Dual-band feed array; 2. Positive front-feed single reflector; 1-1. Low-frequency feed subarray; 1-2. High-frequency feed subarray; 1-3. Arc-shaped mounting surface; 1-1-1. Low-frequency complementary structure variable-angle log-periodic antenna; 1-1-2. Low-frequency dielectric support; 1-2-1. High-frequency complementary structure variable-angle log-periodic antenna; 1-2-2. High-frequency metal reflector; 1-2-3. High-frequency cylindrical support. Detailed Implementation

[0037] The embodiments of the present invention will now be described with reference to the accompanying drawings. The terminology used in the embodiments section is for illustrative purposes only and is not intended to limit the scope of the invention. The embodiments of this application will now be described with reference to the accompanying drawings.

[0038] Example: A dual-band, ultra-wideband, multi-beam, dual-polarized positive feedforward reflector antenna, reference... Figure 1 It includes: a positive feedforward single reflector 2 and a dual-band feed array 1. The dual-band feed array 1 is located near the focal point of the reflector and is longitudinally focused towards the reflector. The main beam of each feed on the dual-band feed array 1 points towards the positive feedforward single reflector 2. The longitudinal projected diameter of the positive feedforward single reflector 2 is... Satisfying the equation of a parabola ,in , The transverse coordinate axis is for the positive feedforward single reflector 2. The vertical axis is the coordinate axis. The focal length of the positive feedforward single reflector 2;

[0039] The dual-band feed array 1 includes a high-frequency feed subarray 1-2 and a low-frequency feed subarray 1-1, as referenced. Figure 2 As shown, each feed in the high-frequency feed subarray 1-2 and the low-frequency feed subarray 1-1 is focused into a narrow beam by a positive feedforward single reflector. Multiple narrow beams form a multi-beam structure, and each feed is polarized into a double circular polarization after being focused by a positive feedforward single reflector 2.

[0040] The dual-band feed array includes low-band and high-band frequencies, and the bandwidth of the two bands is arbitrary. The beamwidth of each band can be designed according to performance requirements. Within the design bandwidth, the beamwidth of each band can be the same or different. For example, when designing the scheme, the coverage area of ​​the lowest frequency beam is used as the benchmark to achieve zero-loss coverage in the design band.

[0041] For the installation of high-frequency feed subarray 1-2 and low-frequency feed subarray 1-1, refer to... Figure 3As shown, the high-frequency feed subarray 1-2 and the low-frequency feed subarray 1-1 are mounted on the convex surface of the arc-shaped mounting surface 1-3, and the direction of each beam is orthogonal to the tangent direction of the arc-shaped mounting surface 1-3.

[0042] In one exemplary embodiment, reference is made to Figure 3 As shown, adjacent feeds in the low-frequency feed subarray 1-1 are arranged in a triangular pattern, while feeds in the high-frequency feed subarray 1-2 are interspersed within the low-frequency feed subarray; Reference Figure 9 The diagram shows the distribution of the high-frequency feed subarray 1-2 and the low-frequency feed subarray 1-1.

[0043] In one exemplary embodiment, reference is made to Figure 4 and Figure 5 As shown, each feed in the low-frequency feed subarray 1-1 is a dual-circularly polarized feed, which includes a dual-linearly polarized antenna and a dual-circularly polarized forming network. The dual-linearly polarized antenna is a composite log-periodic antenna—a variable-angle log-periodic feed, including a pair of complementary structure variable-angle log-periodic antennas 1-1-1 in the low-frequency band and a dielectric support 1-1-2 in the low-frequency band. The dual-circularly polarized forming network is a 90° hybrid bridge that includes the function of this frequency band. The dual-circularly polarized feed forms a dual-circularly polarized narrow beam after being focused by a positive feed parabolic surface. Each feed in the low-frequency feed subarray works independently, and multiple narrow beams are combined to form a multi-beam. Each beam can achieve coverage without leakage within the designed bandwidth of the low-frequency band within the predetermined coverage gain.

[0044] In one embodiment, reference Figure 4 and Figure 6 As shown, each feed in the high-frequency feed subarray 1-2 is a dual-circularly polarized feed, which includes a dual-linearly polarized antenna and a dual-circularly polarized forming network. The dual-linearly polarized antenna is a composite log-periodic feed—a variable-angle log-periodic feed, including a pair of complementary variable-angle log-periodic antennas 1-2-1 and a high-frequency metal reflector 1-2-2, as well as a high-frequency cylindrical support 1-2-3 at the bottom. The dual-circularly polarized forming network is a 90° hybrid bridge that includes the function of this frequency band. The dual-circularly polarized feed forms a dual-circularly polarized narrow beam after being focused by a positive feedforward parabolic reflector. Each feed in the high-frequency feed subarray works independently, and multiple narrow beams are combined to form a multi-beam. Each beam can achieve coverage within the designed bandwidth of the high-frequency band within the predetermined coverage gain, achieving zero-loss coverage in the middle.

[0045] refer to Figure 5 and Figure 6 As shown, the complementary structure variable-angle log-periodic antenna employs a cross-shaped variable-angle log-periodic dipole; reference Figure 8 As shown, a metal reflector and a complementary log-periodic oscillator support are provided to support two pairs of complementary log-periodic oscillators on the metal reflector.

[0046] In one embodiment, reference Figure 7 The image shows an example of a variable-angle log-periodic antenna. This antenna can consist of a regular log-periodic antenna and a metal reflector; it can also consist of a variable-angle log-periodic antenna, a V-shaped antenna, and a metal reflector; or it can consist of a variable-angle log-periodic antenna and a metal reflector.

[0047] In a specific case, the aperture of the positive feed single reflector is D meters, the focal length is F meters, the radius of the spherical equation of the arc surface is L meters, the aperture of the typical frequency of the arc surface is D1 meters, the high and low frequency bands are a continuous frequency band, the high-low sideband ratio of the low frequency band is 3.56, and the high-low sideband ratio of the high frequency band is 3.375; the high-low frequency ratio of the antenna across the entire frequency band is 12; the high-frequency feed subarray 1-2 has a total of 31 dual-circular polarized feeds, which, after being focused by the reflector, form 31 narrow beams; the low-frequency feed subarray 1-1 has a total of 24 dual-circular polarized feeds, which, after being focused by the reflector, form 24 narrow beams.

[0048] Based on the above, refer to Figure 10 As shown, the frequencies are in the low-frequency band. The multi-beam coverage pattern consists of 24 narrow beams, as referenced. Figure 11 As shown, this is the low-frequency band. The multi-beam coverage pattern consists of 24 narrow beams, as referenced. Figure 12 As shown, the high-frequency band has a frequency of Multi-beam coverage pattern, consisting of 31 narrow beams; Reference Figure 13 As shown, the high-frequency band has a frequency of The multi-beam coverage pattern consists of 31 narrow beams.

[0049] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. For those skilled in the art, after learning the contents described in the present invention, several equivalent changes and substitutions can be made without departing from the principle of the present invention. These equivalent changes and substitutions should also be considered to fall within the protection scope of the present invention.

Claims

1. A dual-band, ultra-wideband, multi-beam, dual-polarized positive feedforward reflector antenna, characterized in that, include: Positive feedforward single reflector; The dual-band feed array is configured to be longitudinally focused towards the positive feed single reflector, and the main beam of each feed on the feed array points towards the positive feed single reflector; and The dual-band feed array includes a high-frequency feed subarray and a low-frequency feed subarray. Each feed in the high-frequency feed subarray and the low-frequency feed subarray is focused into a narrow beam by a positive feedforward single reflector, and each feed is polarized into dual circular polarization after being focused by the positive feedforward single reflector. Each feed in the low-frequency band feed subarray is a dual-circular polarization feed, and the feed includes a dual-linear polarization antenna and a dual-circular polarization forming network. The dual-polarized antenna in each feed of the low-frequency feed subarray includes a pair of complementary structure variable angle log-periodic antennas in the low-frequency band and a dielectric support in the low-frequency band. The dual-circular polarization forming network includes a 90° hybrid bridge with corresponding frequency band functions. The high-frequency feed subarray is a dual-circular polarization feed, which includes a dual-linear polarization antenna and a dual-circular polarization forming network. Each feed in the high-frequency feed subarray includes a pair of complementary structure variable angle log-periodic antennas and a high-frequency metal reflector; and a high-frequency cylindrical support at the bottom. The dual-circular polarization forming network includes a 90° hybrid bridge with corresponding frequency band functions.

2. The dual-band, ultra-wideband, multi-beam, dual-polarized positive feedforward reflector antenna according to claim 1, characterized in that: Each feed in the low-frequency band feed subarray operates independently, and multiple narrow beams are combined to form a multi-beam array. Each beam can achieve the designed bandwidth in the low-frequency band within a predetermined coverage gain.

3. The dual-band, ultra-wideband, multi-beam, dual-polarized positive feedforward reflector antenna according to claim 1, characterized in that: Each feed in the high-frequency feed subarray operates independently, and multiple narrow beams are combined to form a multi-beam array. Each beam can achieve the designed bandwidth in the high-frequency band within a predetermined coverage gain.

4. The dual-band, ultra-wideband, multi-beam, dual-polarized positive feedforward reflector antenna according to claim 1, characterized in that: The dual-band feed array includes low-band and high-band frequencies, and the bandwidth of the two bands is arbitrary.

5. The dual-band, ultra-wideband, multi-beam, dual-polarized positive feedforward reflector antenna according to claim 1, characterized in that: The adjacent feeds in the low-frequency feed subarray are arranged in a triangular pattern, and the feeds in the high-frequency feed subarray are interspersed in the low-frequency feed subarray.

6. The dual-band, ultra-wideband, multi-beam, dual-polarized positive feedforward reflector antenna according to claim 5, characterized in that: The dual-band feed array also includes an arc-shaped mounting surface. The high-frequency band feed subarray and the low-frequency band feed subarray are mounted on the convex surface of the arc-shaped mounting surface, and the direction of each beam is orthogonal to the tangent direction of the arc-shaped mounting surface.

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