Microwave absorbing structure and method for suppressing cross-polarization of dual-polarized waveguide slot array antenna

Abstract

The invention provides a microwave absorbing structure and a method for restraining cross polarization of a dual-polarization waveguide slot array antenna. The microwave absorbing structure is characterized in that the number of elements of a horizontal polarization waveguide wide-edge slot array (1) times half of a waveguide length equals the length of a cuboid; the width of the cuboid is less than the distance from a slot of a perpendicular polarization waveguide narrow-edge slot array (2) to the upper surface of the horizontal polarization waveguide wide-edge slot array (1); the thickness of the cuboid is equal to 0.01-0.05 wavelength within the working band; a small cuboid concave opening is cut at an interval of half of the waveguide wavelength from the upper surface of the cuboid; and the outline of the cut concave opening is 0.02-0.04 wavelength greater than that of the waveguide narrow-wedge slot.

Description

technical field [0001] The invention relates to the field of microwave technology, in particular to a common-aperture dual-polarized waveguide slot array antenna Background technique [0002] Airborne SAR radar uses high-power, low-loss common-aperture dual-polarization waveguide slot array antenna technology, which not only reduces the loading space of the antenna, but also increases the amount of information and improves the accuracy of identifying targets. However, the application of dual-polarization technology usually requires the antenna to have a low cross-polarization level to ensure a high degree of isolation between the two signals. For the traditional co-aperture dual-polarization waveguide slot array antenna, this The indicators are far from the requirements. [0003] In May 2005, Wang Wei, Jin Jian, etc. published an article titled "Broadband Diaphragm Excited Waveguide Narrow Side Non-Sloped Slot Array Antenna" on the "Acta Microwave Sinica" which changed the ...

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Problems solved by technology

It is explained in the paper that these additional installation methods will raise the side lobe and affect the radiation of the main polarization, and a new method is proposed, that is, by adjusting the distance between the antenna and the floor, the cross-polarized reflected wave and the direct wave cancel each other, and the cross-polarized The level can be reduced by 6dB, but this method is suitable for narrow-band narrow-side slot arrays, and the distance between the slot array and the antenna floor is too large, which obviously increases the thickness of the antenna

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