CN-115995680-B - Flexible combined multifunctional broadband ultra-surface antenna for synthetic aperture radar

CN115995680BCN 115995680 BCN115995680 BCN 115995680BCN-115995680-B

Abstract

The embodiment of the disclosure discloses a flexible combined type multifunctional broadband super-surface antenna for a synthetic aperture radar, wherein the broadband super-surface antenna comprises a core super-surface antenna positioned at a central position and a peripheral super-surface positioned at a peripheral position from inside to outside, the core super-surface antenna and the peripheral super-surface are connected through a U-shaped groove plug structure, and the core super-surface antenna and the peripheral super-surface with different structures can be replaced according to different application scenes. The method has the characteristics of simple and reliable modularized structure and flexible configuration according to task requirements, meets the requirements of high-precision multiple emission modes and corresponding consistent multi-polarization reception of the synthetic aperture radar, can effectively increase the working bandwidth of the core antenna under a low profile, reduces the radar scattering area of the antenna, optimizes the antenna radiation pattern and reduces the cross coupling characteristic, further improves the imaging performance of the synthetic aperture radar, and reduces the signal-to-interference ratio of a synthetic aperture radar system.

Inventors

LIU KAIYU
LI HUA
LI ZHENNING
REN MINGSHAN
WEN YUHAO
DENG YUNKAI

Assignees

中国科学院空天信息创新研究院

Dates

Publication Date: 20260505
Application Date: 20230119

Claims (9)

1. The flexible combined type multifunctional broadband super-surface antenna for the synthetic aperture radar is characterized by comprising a core super-surface antenna positioned at a central position and a peripheral super-surface positioned at a peripheral position from inside to outside, wherein the core super-surface antenna and the peripheral super-surface are connected through a U-shaped groove plug structure, and the core super-surface antenna and the peripheral super-surface with different structures can be replaced according to different application scenes; The core super-surface antenna works in an X-band and is formed by compactly stacking two dielectric substrates with the thickness of 1mm, a super-surface antenna layer, a microstrip feeder layer and a metal stratum, wherein the two dielectric substrates are respectively arranged between the super-surface antenna layer and the microstrip feeder layer and between the microstrip feeder layer and the metal stratum, no air gap exists between different layers, square peripheral chamfer radiation patch units which are distributed in a 3X 3 equidistant rectangular unit grid are arranged on the super-surface antenna layer, two side-feed microstrip lines in an inductive coupling excitation mode are arranged on the microstrip feeder layer, each side-feed microstrip line is connected with 1 signal input port, the phase difference of input signals of the signal input ports connected with the two side-feed microstrip lines is 90 degrees, and the metal stratum is arranged on the bottom side of the lower dielectric substrate; The peripheral super surface is formed by arranging passive I-type unit arrays with the same orientation as 3X 3 in a horizontal plane, the gaps between adjacent arrays are 2.9-3.1mm, the arrangement direction of the passive I-type unit arrays is in the vertical or horizontal direction in the horizontal plane, the overall layout is obtained in a topology optimization mode, and the passive I-type unit arrays are in random arrangement.
2. The flexible combined type multifunctional broadband super-surface antenna for the synthetic aperture radar of claim 1, wherein the passive I-type unit array comprises a radiation metal layer, a single-layer dielectric substrate layer and a metal stratum which are sequentially arranged from top to bottom, the overall thickness is 3.8mm, and no air gap exists between different layers.
3. A flexible combined type multifunctional broadband super-surface antenna for a synthetic aperture radar as claimed in claim 2, wherein the radiating metal layer of the passive I-type unit array is composed of I-type metal strips, the radiating metal layer is located at the center of the super-surface unit, the radiating metal layer is 6.3mm long and 3.6mm wide, the distance between two adjacent I-type metal strips is 5.9-7.1mm, rectangular metal tuning branches with the same length and width are arranged at the upper end and the lower end of each I-type metal strip, the radiating metal layer is symmetrically distributed about the center of the passive I-type unit array unit, the distance between the tuning branches of the two adjacent I-type metal strips is 0.4-0.6mm, the single-layer dielectric substrate layer is a homogeneous dielectric plate without metallized through holes, the relative dielectric constant is 2-4.5, the metal layer is a homogeneous metal plate, and a gap is not etched.
4. A flexible combined type multifunctional broadband super-surface antenna for a synthetic aperture radar is characterized in that the peripheral super-surface antenna is formed by periodically and circularly arranging PIN diode super-surface units which are digitally controlled in a horizontal plane, the gaps between every two adjacent PIN diode super-surface units are 2.0-2.2mm, the arrangement direction of the PIN diode super-surface units is along the vertical direction in the horizontal plane, the number of arranged rows and columns are the same, the overall layout of the peripheral super-surface antenna is square, and the width of the peripheral super-surface antenna is 280mm.
5. The flexible combined type multifunctional broadband super-surface antenna for the synthetic aperture radar of claim 4, wherein the digitally controlled PIN diode super-surface unit comprises a top radiation metal layer, a single-layer dielectric substrate layer, a bottom metal layer and two metallized through holes which are sequentially arranged from top to bottom, the overall thickness is only 3.8mm, and no air gap exists between different layers.
6. A flexible combined type multifunctional broadband super-surface antenna for a synthetic aperture radar is characterized in that a top radiation metal layer of a digital control PIN diode super-surface unit is formed by symmetrically distributing centers of two radiators, the tail ends of the top radiation metal layer are open circuits, meanwhile, the centers of the PIN diode super-surface unit are connected with the two centers of the two radiators in a symmetrical mode through a radio frequency PIN diode, the single-layer dielectric substrate layer is a homogeneous dielectric plate and is provided with two metallized through holes, an L-shaped metal strip is electrically connected with bottom metal, the metallized through holes are symmetrical with respect to the center of a radio frequency switch, voltage controls on-off of the radio frequency switch through the metallized through holes, the relative dielectric constant is 2-4.5, the bottom metal layer is a homogeneous metal plate, a metal gap is etched in the center of the unit along the placement direction of the radio frequency switch, the metal gap divides the bottom metal layer into two parts, and good on-off of the radio frequency switch is guaranteed when direct current bias is applied.
7. A flexible combined type multifunctional wideband ultra-surface antenna for synthetic aperture radar as claimed in claim 6, wherein each radiator of said top layer radiating metal layer is formed by connecting two L-shaped metal strips, the first L-shaped metal strip is rotationally symmetrically connected with respect to a radio frequency switch, the top width is 1.9-2.2mm, the longitudinal length is 3.6-4.4mm, the second L-shaped metal strip is opened at the tail end, the other end is connected with the tail end of the first L-shaped metal strip, the two L-shaped metal strips are rotationally symmetrically distributed with respect to the radio frequency switch, the top width is 2.6-3.0mm, the longitudinal length is 5.0-5.6mm, the longitudinal gap distance between the two metal strips is 0.26-0.27mm, and the transverse gap distance is 0.25-0.75mm.
8. The flexible combined type multifunctional broadband super-surface antenna for the synthetic aperture radar as claimed in claim 6 or 7, wherein the value range of a metal gap etched in the bottom metal stratum is 0.16-0.18mm, and the metal strata on two sides of the metal gap are also used as electrodes to be respectively connected with the positive electrode and the negative electrode of an external driving power supply.
9. A flexible combined type multifunctional broadband super-surface antenna for a synthetic aperture radar, as claimed in claim 1, wherein the U-shaped slot plugging structure comprises a U-shaped protrusion at the center position of the cross section of the core super-surface antenna and a U-shaped groove of the peripheral super-surface at the center position of the cross section, the thickness dimensions of the U-shaped protrusion and the U-shaped groove are the same, the thickness dimension of the U-shaped protrusion and the U-shaped groove are 1/3 of the whole thickness of 1.3mm, the length of the U-shaped protrusion is 6mm, and the depth of the U-shaped groove is 5.8mm, so that interference fit is realized.

Description

Flexible combined multifunctional broadband ultra-surface antenna for synthetic aperture radar Technical Field The disclosure relates to the technical field of synthetic aperture radars, in particular to a flexible combined type multifunctional broadband super-surface antenna for a synthetic aperture radar. Background Synthetic Aperture Radar (SAR) is evolving toward multi-polarization, high resolution, large breadth, multi-spectrum and multi-mode. Radar antennas are an important component of SAR systems, determining their performance, their beam shape and beam scanning capability will affect SAR range and azimuth resolution, imaging ambiguity, system sensitivity and swath bandwidth, etc. With advances in radar science and technology, the design of synthetic aperture radar antennas has also faced new challenges. Currently, in the SAR system, the waveguide slot array antenna is widely used due to the characteristics of low cost, convenient and fast processing, high precision, compact structure, high gain, easy control of caliber distribution and the like, such as an antenna of an SIR-C SAR satellite which is commonly designed and produced by the U.S. space agency (NASA) and the pall (Ball) space company, and an antenna of a Radarsat-II SAR satellite which is designed and developed by the German space agency (DLR) and the dornier company. However, with the development of high-resolution wide-width technology, the SAR system needs a wider working bandwidth, so that the complexity of the waveguide slot array antenna structure is greatly increased, and the processing difficulty and the cost are increased. In addition, the development of some new regime concepts such as multiband, multipole, variable view and variable beamwidth, miniaturized ultra-light air SAR arrays, etc. requires more compact, integrated, solid state, and iteratively debugged modular antennas. In increasingly complex electromagnetic environments, how to improve the signal-to-noise ratio of the SAR system through the antenna, reduce the radar reflection area of the SAR, and improve the stealth and safety of the SAR imaging system is also an increasingly focused topic. In summary, how to provide a flexible combined type multifunctional wideband antenna easy to iteratively debug is a significant problem based on the existing SAR system antenna and around the requirements of multifunction, compact integration and easy to iteratively debug. Disclosure of Invention The embodiment of the disclosure provides a flexible combined type multifunctional broadband super-surface antenna for a synthetic aperture radar. According to the first aspect, the embodiment of the disclosure provides a flexible combined type multifunctional broadband super-surface antenna for a synthetic aperture radar, which is characterized by comprising a core super-surface antenna located at a central position and a peripheral super-surface located at a peripheral position from inside to outside, wherein the core super-surface antenna and the peripheral super-surface are connected through a U-shaped groove plug structure, and the core super-surface antenna and the peripheral super-surface with different structures can be replaced according to different application scenes. The core super-surface antenna works in an X-band, is formed by compactly stacking two dielectric substrates with the thickness of 1mm, a super-surface antenna layer, a microstrip feeder layer and a metal stratum, wherein the two dielectric substrates are respectively arranged between the super-surface antenna layer and the microstrip feeder layer and between the microstrip feeder layer and the metal stratum, no air gap exists between different layers, square surrounding corner-cut radiation patch units which are distributed in a 3X 3 equidistant rectangular unit grid mode are arranged on the super-surface antenna layer, two side-feed microstrip lines which are in inductive coupling excitation mode are arranged on the microstrip feeder layer, each side-feed microstrip line is connected with 1 signal input port, the phase difference of input signals of the signal input ports connected with the two side-feed microstrip lines is 90 degrees, and the metal stratum is arranged on the bottom side of the lower dielectric substrate. Further, the peripheral super surface is formed by arranging passive I-shaped cell arrays with the same 3X 3 orientation in a horizontal plane, the gaps between adjacent arrays are 2.9-3.1mm, the arrangement direction of the passive I-shaped cell arrays is in the vertical or horizontal direction in the horizontal plane, the overall layout of the passive I-shaped cell arrays is obtained in a topology optimization mode, and the passive I-shaped cell arrays are in random arrangement patterns. Further, the passive I-type cell array comprises a radiation metal layer, a single-layer dielectric substrate layer and a metal stratum which are sequentially arranged from top to bottom, the overall thicknes