Multiband integrated antenna applied to airborne temperature and humidity profiler

Abstract

The invention discloses a multiband integrated antenna applied to an airborne temperature and humidity profiler, and the integrated antenna comprises a main reflection surface, the projection clear aperture of the main reflection surface employs a 90-degree off-axis paraboloid design, an incident wave beam is perpendicular to the rotation axis of the main reflection surface, and a convergent wave beam is generated after parallel light is received; the four-waveband quasi-optical feed point network is composed of a first-stage frequency selection surface and a second-stage frequency selection surface, and the first-stage frequency selection surface receives the convergent wave beams generated by the main reflection surface and transmits the wave beams to the second-stage frequency selection surface; according to the multi-band common-aperture antenna integration technology, compact optical layout design is adopted, system envelope as small as possible can be achieved, and the requirement for the small size of an airborne platform is met; the frequency divider adopts frequency selection surfaces in a quasi-optical form, and the separation of four working frequency bands is realized through the combined use of the three frequency selection surfaces; and a modular design is adopted, so that the debugging difficulty is reduced, and the system maintainability is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of microwave radiometers, and in particular relates to a multi-band integrated antenna applied to an airborne temperature and humidity profiler. Background Art

[0002] Airborne temperature and humidity profilers are mainly used for remote sensing of the atmosphere below the route. They can achieve remote sensing detection and inversion of parameters such as the atmospheric temperature and humidity profile below the route by passively detecting the atmospheric radiation information of the oxygen channel V band (51-59 GHz) and F band (113-120 GHz), the water vapor channel G band (173-183 GHz), and the window area W band. As the core subsystem of the airborne temperature and humidity profiler, the performance of the multi-band antenna directly determines the detection accuracy of the profiler. There are no reports of finished airborne temperature and humidity profilers in China. Most foreign airborne profilers use a single-band fixed single reflector. When there are many bands, the volume is large and cannot meet the small volume requirements of the airborne platform, and angle scanning cannot be achieved. Therefore, it is necessary to consider a common aperture antenna integration technology to share the same reflector with antennas of multiple bands to overcome the large volume and fixed beam of the single-band single reflector. Summary of the invention

[0003] The object of the present invention is to provide a multi-band integrated antenna for an airborne temperature and humidity profiler to solve the problem in the above background technology that the airborne temperature and humidity profiler has many working bands and many corresponding antenna horns and reflecting surfaces.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a multi-band integrated antenna applied to an airborne temperature and humidity profiler, the integrated antenna comprising a main reflector, the main reflector projects a light-clearance aperture, adopts a 90° off-axis parabola design, the incident beam is perpendicular to the rotation axis of the main reflector, and generates a convergent beam after receiving parallel light; a four-band quasi-optical feeding point network, composed of a primary frequency selective surface and a secondary frequency selective surface, wherein the primary frequency selective surface receives the generated convergent beam of the main reflector and transmits the beam to the secondary frequency selective surface; the energy radiated by the atmosphere passes through the antenna cover, is received by the main reflector, and then changes the transmission direction through the main reflector, and the quasi-optical feeding network realizes the separation of the four working frequency bands of V / W / F / G through the combined use of three high-pass frequency selective surfaces.

[0005] As a preferred technical solution in the present invention, the primary frequency selective surface is divided into a V / W frequency selective surface for the reflected beam and a F / G frequency selective surface for the transmitted beam. The V / W frequency selective surface is divided into a V band and a W band after passing through the secondary frequency selective surface, and the F / G frequency selective surface is divided into an F band and a G band after passing through the secondary frequency selective surface; the function of multi-band multiplexing is realized by a quasi-optical frequency selective surface FSS. For the FSS in the form of an array aperture, each aperture can be regarded as a small section of a waveguide. When the frequency of the incident plane wave is below the waveguide cutoff frequency, most of the plane wave energy is reflected; when the frequency of the incident plane wave is greater than the cutoff frequency, most of the incident energy is transmitted, so it can be used as a high-pass filter. In this antenna system, the energy radiated by the atmosphere passes through the radome, is received by the main reflector, and then changes the transmission direction through the main reflector. The quasi-optical feeding network realizes the separation of the four working frequency bands of V / W / F / G by combining three high-pass frequency selective surfaces.

[0006] As a preferred technical solution in the present invention, the G-band, F-band, V-band and W-band are respectively provided with a G-band feed horn, an F-band feed horn, a V-band feed horn and a W-band feed horn, the feed horn determines the antenna aperture field distribution and the polarization mode of the final radiation beam of the antenna, and the inner wall profile of the circular horn is optimized to achieve precise control of different waveguide excitation modes, thereby obtaining an ideal directivity diagram and excellent port standing wave ratio characteristics, while the processing difficulty and cycle are greatly reduced compared with the traditional corrugated horn, and the G-band and F-band are provided with an F-band ellipsoidal reflector, the V-band is provided with a V-band ellipsoidal reflector, and the W-band is provided with a W-band ellipsoidal reflector; wherein the beams of the F-band, V-band and W-band are respectively received by the F-band feed horn, the V-band feed horn and the W-band feed horn after being refocused by the F-band feed horn, the V-band feed horn and the W-band feed horn.

[0007] As a preferred technical solution in the present invention, a W-band plane reflector for realizing optical path turning is arranged in front of the W-band feed horn.

[0008] As a preferred technical solution in the present invention, the main reflecting surface is installed on the rotating motor of the antenna servo unit through the main surface support structure. The motor drives the main reflecting surface to rotate around the main optical axis to realize antenna beam scanning. Precise positioning is achieved between the mirror base and the substrate through pins.

[0009] As a preferred technical solution in the present invention, each quasi-optical element is fixed on the same substrate through an independent lens holder, and the substrate also serves as a reference surface for mounting and positioning each quasi-optical element.

[0010] As a preferred technical solution in the present invention, the W-band plane reflector and the W-band ellipsoid reflector are staggered and receive the beam of the W-band ellipsoid reflector.

[0011] Compared with the prior art, the present invention has the following beneficial effects: 1. The multi-band common aperture antenna integration technology of the present invention adopts a compact optical layout design to achieve the smallest possible system envelope, which is suitable for the small volume requirements of airborne platforms; 2. The frequency divider adopts a quasi-optical frequency selective surface, and the separation of four working frequency bands is achieved through the combined use of three frequency selective surfaces; 3. A zoom reflector is arranged in front of the feed horn of each band, so that the beam incident on the frequency selective surface is as close to a plane wave as possible; 4. The modular design reduces the difficulty of debugging and improves the maintainability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a layout diagram of the optical path design of the multi-band common aperture integrated antenna of the present invention; Figure 2 This is a structural diagram of the multi-band common aperture integrated antenna of the present invention.

[0013] In the figure: 1. V / W frequency selective surface; 2. VW / FG frequency selective surface; 3. F / G frequency selective surface; 4. G-band feed horn; 5. F-band feed horn; 6. V-band feed horn; 7. W-band feed horn; M1, main reflector; M2, V-band ellipsoidal reflector; M3, W-band ellipsoidal reflector; M4, F-band ellipsoidal reflector; M5, W-band plane reflector. DETAILED DESCRIPTION

[0014] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0015] See also Figure 1 and Figure 2 The present invention provides a technical solution: a multi-band integrated antenna for an airborne temperature and humidity profiler, the integrated antenna comprising A main reflector M1, the projected aperture of the main reflector M1 is 100 mm, and a 90° off-axis parabola design is adopted. The incident beam is perpendicular to the rotation axis of the main reflector M1, and a convergent beam is generated after receiving parallel light; A four-band quasi-optical feeding point network is composed of a primary frequency selective surface and a secondary frequency selective surface, wherein the primary frequency selective surface receives the convergent beam generated by the main reflector M1 and transmits the beam to the secondary frequency selective surface; the energy radiated by the atmosphere passes through the antenna cover, is received by the main reflector M1, and then changes the transmission direction through the main reflector M1. The quasi-optical feeding network realizes the separation of the four working frequency bands of V / W / F / G through the combined use of three high-pass frequency selective surfaces.

[0016] In this embodiment, the primary frequency selective surface, namely the VW / FG frequency selective surface 2, is divided into the V / W frequency selective surface 1 of the reflected beam and the F / G frequency selective surface 3 of the transmitted beam. After passing through the secondary frequency selective surface, the V / W frequency selective surface 1 is divided into the V band and the W band, and after passing through the secondary frequency selective surface, the F / G frequency selective surface 3 is divided into the F band and the G band; the function of multi-band multiplexing is realized by the quasi-optical frequency selective surface FSS. For the FSS in the form of array aperture, each aperture can be regarded as a small section of waveguide. When the frequency of the incident plane wave is below the waveguide cutoff frequency, most of the plane wave energy is reflected; when the frequency of the incident plane wave is greater than the cutoff frequency, most of the incident energy is transmitted, so it can be used as a high-pass filter. In this antenna system, the energy radiated by the atmosphere passes through the radome, is received by the main reflector, and then changes the transmission direction through the main reflector. The quasi-optical feeding network realizes the separation of the four working frequency bands of V / W / F / G through the combination of three high-pass frequency selective surfaces.

[0017] In this embodiment, G-band, F-band, V-band and W-band feed horns 4, 5, 6 and 7 are provided respectively on the G-band, F-band, V-band and W-band. The feed horns determine the field distribution of the antenna aperture and the polarization mode of the final radiation beam of the antenna. By optimizing the inner wall profile of the circular horn, precise control of different waveguide excitation modes is achieved, thereby obtaining an ideal radiation pattern and excellent port standing wave ratio characteristics. At the same time, the processing difficulty and The period is greatly reduced compared with the traditional corrugated horn, and an F-band ellipsoidal reflector M4 is provided on the G-band and F-band, a V-band ellipsoidal reflector M2 is provided on the V-band, and a W-band ellipsoidal reflector M3 is provided on the W-band; wherein the beams of the F-band, V-band and W-band are refocused by the F-band feed horn 5, the V-band feed horn 6 and the W-band feed horn 7 respectively, and then received by the F-band feed horn 5, the V-band feed horn 6 and the W-band feed horn 7 respectively.

[0018] In this embodiment, a W-band plane reflector M5 is disposed in front of the W-band feed horn 7 for realizing the optical path turning.

[0019] In this embodiment, the main reflection surface M1 is installed on the rotating motor of the antenna servo unit through the main surface support structure. The motor drives the main reflection surface M1 to rotate around the main optical axis to realize antenna beam scanning. The pins are used to achieve precise positioning between the mirror base and the substrate.

[0020] In this embodiment, each quasi-optical element is fixed on the same substrate through an independent lens holder, and the substrate also serves as a reference surface for mounting and positioning each quasi-optical element.

[0021] In this embodiment, the W-band plane reflector M5 is staggered with the W-band ellipsoid reflector M3 and receives the beam of the W-band ellipsoid reflector M3.

[0022] Although embodiments of the present invention have been shown and described (see the above detailed description for details), it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A multi-band integrated antenna for an airborne temperature and humidity profiler, characterized in that: The integrated antenna includes a main reflection surface (M1), the incident beam is perpendicular to the rotation axis of the main reflection surface (M1), and generates a convergent beam after receiving parallel light; A four-band quasi-optical feed point network is composed of a primary frequency selective surface and a secondary frequency selective surface, wherein the primary frequency selective surface receives a convergent beam generated by a main reflection surface (M1) and transmits the beam to the secondary frequency selective surface.

2. The multi-band integrated antenna for use in an airborne temperature and humidity profiler according to claim 1, characterized in that: The primary frequency selective surface is divided into a V / W frequency selective surface (1) for the reflected beam and an F / G frequency selective surface (3) for the transmitted beam. The V / W frequency selective surface (1) is divided into a V band and a W band after passing through the secondary frequency selective surface, while the F / G frequency selective surface (3) is divided into an F band and a G band after passing through the secondary frequency selective surface.

3. The multi-band integrated antenna for use in an airborne temperature and humidity profiler according to claim 2, characterized in that: The G band, F band, V band and W band are respectively provided with a G band feed horn (4), an F band feed horn (5), a V band feed horn (6) and a W band feed horn (7); the G band and the F band are provided with an F band ellipsoid reflector (M4); the V band is provided with a V band ellipsoid reflector (M2); and the W band is provided with a W band ellipsoid reflector (M3); wherein the beams of the F band, the V band and the W band are respectively refocused by the F band feed horn (5), the V band feed horn (6) and the W band feed horn (7) and are respectively received by the F band feed horn (5), the V band feed horn (6) and the W band feed horn (7).

4. The multi-band integrated antenna for use in an airborne temperature and humidity profiler according to claim 3, characterized in that: A W-band plane reflector (M5) for realizing optical path turning is arranged in front of the W-band feed horn (7).

5. The multi-band integrated antenna for use in an airborne temperature and humidity profiler according to claim 1, characterized in that: The main reflection surface (M1) is mounted on a rotating motor of an antenna servo unit via a main surface support structure, and the motor drives the main reflection surface (M1) to rotate around a main optical axis.

6. The multi-band integrated antenna for use in an airborne temperature and humidity profiler according to claim 5, characterized in that: Each quasi-optical element is fixed on the same substrate through an independent lens seat, and the substrate also serves as a reference surface for mounting and positioning each quasi-optical element.

7. The multi-band integrated antenna for use in an airborne temperature and humidity profiler according to claim 4, characterized in that: The W-band plane reflector (M5) is arranged in a staggered manner with the W-band ellipsoid reflector (M3), and receives the beam of the W-band ellipsoid reflector (M3).

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