CN-116207520-B - X-band low-profile broadband double-circularly polarized super-surface antenna

Abstract

The embodiment of the disclosure discloses an X-band low-profile broadband double-circular polarization super-surface antenna, which comprises two layers of dielectric substrates and three layers of metal layers, wherein the three layers of metal layers comprise a super-surface antenna layer, a microstrip feeder layer and a metal stratum, one layer of the two layers of dielectric substrates is respectively arranged between the super-surface antenna layer and the microstrip feeder layer and between the microstrip feeder layer and the metal stratum to form a compact stacked structure, no air gap exists between the two layers of dielectric substrates and the three layers of metal layers, and 3X 3 radiating patch units distributed at equal intervals are arranged on the super-surface antenna layer, and each radiating patch unit is in a square corner-cut shape. The X-band low-profile broadband dual-circular polarization super-surface antenna has the characteristics of compact structure, wide working bandwidth, wide normal 3dB circular polarization axis, high normal gain, multiple polarization modes and the like.

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

20230114

Claims (2)

1. 1. The X-band low-profile broadband double-circular polarization super-surface antenna is characterized by comprising two dielectric substrates and three metal layers, wherein the three metal layers comprise a super-surface antenna layer, a microstrip feeder layer and a metal stratum, one of the two dielectric substrates is respectively arranged between the super-surface antenna layer and the microstrip feeder layer and between the microstrip feeder layer and the metal stratum to form a compact stacked structure, no air gap exists between the two dielectric substrates and the three metal layers, and 3X 3 radiating patch units which are distributed and arranged at equal intervals are arranged on the super-surface antenna layer, and each radiating patch unit is in a square corner cutting shape; the four square chamfer angles of the radiation patch units are distributed in a central symmetry manner, and the radiation patch units distributed and arranged at equal intervals of 3 multiplied by 3 are centrally symmetric about an intersection point Z of an X axis and a Y axis of the linear polarization direction of the antenna; Grid arrangement intervals of the radiation patch units distributed and arranged at equal intervals on the super-surface antenna layer and the shape and the size of the radiation patch units are optimally designed through a characteristic mode theory; When grid arrangement space and shape size of a radiation patch unit on an antenna layer are optimally designed by utilizing a characteristic mode theory, designing a broadband circularly polarized antenna by utilizing a1 st and a2 nd characteristic modes with minimum characteristic values and maximum mode factors in the first eight characteristic modes of the radiation patch unit to obtain the arrangement space 1mm and shape size of the radiation patch unit; and according to the characteristic that the current direction in the characteristic mode theory is along the edge direction of the radiation patch unit, adopting a side-fed inductive coupling excitation mode in the microstrip feeder line layer.
2. 2. The X-band low-profile broadband dual circularly polarized ultra-surface antenna according to claim 1, wherein two side-fed microstrip lines of the microstrip feeder layer adopting an inductive coupling excitation mode are respectively connected with a signal input port, the phase difference of input signals of the signal input ports is 90 degrees, and blind insertion butt joint is performed between the signal input ports and the signal cable by adopting SMA and RP-SMA connectors.

Description

X-band low-profile broadband double-circularly polarized super-surface antenna Technical Field The disclosure relates to the technical field of radio frequency antenna equipment engineering of a synthetic aperture radar system, in particular to an X-band low-profile broadband dual-circularly polarized super-surface antenna. Background As one of the most leading technologies in the field of earth observation, synthetic Aperture Radar (SAR) has been widely used in many fields such as remote sensing, microwave mapping, etc. by virtue of its all-weather and high-resolution observation capability. As science and technology advances, the design of SAR systems also faces new challenges. The X-band SAR is of great interest because of its small size and light weight, and the device is mature and stable, which means that the complexity of the system is greatly reduced. Antennas located at the very front of the spaceborne SAR systems are now subject to high gain performance requirements to cope with the spatial losses of electromagnetic waves, while maintaining small dimensions for good integration into electrical systems. Conventional metal reflector antennas and horn antennas have the advantages of high gain and high efficiency, but the polarization mode is too single, and the volume and weight may be too heavy to be integrated into a SAR system. Microstrip antennas have been attracting attention in the design of X-band SAR, and conventional antenna elements based on compact design of electric dipoles and magnetic dipoles and having high gain are inferior to metals in stability of substrates in severe environments of high and low temperatures in space environments. The ultra-surface microstrip patch antenna has the advantages of high gain, high efficiency, small appearance, various planning modes and the like, and the metal is insensitive to temperature change, so that the ultra-surface microstrip patch antenna is very suitable for the design of the radio frequency front end in the X-band airborne and satellite-borne SAR systems. In summary, how to design and manufacture a low-profile antenna with high gain, wide bandwidth and multiple polarizations based on the SAR system is a significant problem. Disclosure of Invention The embodiment of the disclosure provides an X-band low-profile broadband dual circularly polarized super-surface antenna. According to the first aspect, the embodiment of the disclosure provides an X-band low-profile broadband dual-circularly polarized super-surface antenna, which comprises two dielectric substrates and three metal layers, wherein the three metal layers comprise a super-surface antenna layer, a microstrip feeder layer and a metal stratum, one of the two dielectric substrates is respectively arranged between the super-surface antenna layer and the microstrip feeder layer and between the microstrip feeder layer and the metal stratum to form a compact stacked structure, no air gap exists between the two dielectric substrates and the three metal layers, 3X 3 radiating patch units which are distributed and arranged at equal intervals are arranged on the super-surface antenna layer, and each radiating patch unit is in a square corner cutting shape. Further, the four square cut angles of the radiation patch units are distributed in a central symmetry manner, and the radiation patch units distributed and arranged in a 3×3 equidistant manner are centrally symmetric about an intersection point Z of an X axis and a Y axis of the linear polarization direction of the antenna. Further, grid arrangement intervals of the radiation patch units distributed and arranged at equal intervals on the super-surface antenna layer and shape and size of the radiation patch units are optimally designed through a characteristic mode theory. Further, when the grid arrangement space and the shape size of the radiation patch units on the antenna layer are optimally designed by utilizing the characteristic mode theory, the design of the broadband circularly polarized antenna is performed by utilizing the 1 st and 2 nd characteristic modes with the minimum characteristic values and the maximum mode factors in the first eight characteristic modes of the radiation patch units, so that the arrangement space 1mm and the shape size of the radiation patch units are obtained. Further, according to the characteristic that the current direction in the characteristic mode theory is along the edge direction of the radiation patch unit, a side-fed inductive coupling excitation mode is adopted in the microstrip feeder layer. Further, two side-feed microstrip lines adopting an inductive coupling excitation mode in the microstrip feeder layer are respectively connected with a signal input port, the phase difference of input signals of the signal input ports is 90 degrees, and blind insertion butt joint is carried out between the signal input ports and the signal cables by adopting SMA and RP-SMA connectors. The technical scheme p