Dual-polarization three-passband three-dimensional frequency selective surface

Abstract

The invention discloses a dual-polarization three-passband three-dimensional frequency selective surface. The frequency selective surface is formed by periodically arranging a plurality of same unit structures, and each unit structure is formed by combining a square metal cylinder and a square dielectric block. The upper end face and the lower end face of the square dielectric block have the samestructure and are engraved with two metal square rings, a metal square ring is engraved in the middle layer of the square dielectric block, and the metal square rings on the upper and lower end facesof the square dielectric block and the metal square ring on the middle layer are concentric rings. Due to the electromagnetic coupling effect in the unit structure, a plurality of transmission zero poles are generated, and three passbands are formed. Due to the introduction of a plurality of transmission zeros, the frequency selective filter has good frequency selective performance. And through the design of the metal square rings with very close sizes, the small passband ratio performance is realized. In addition, the frequency selective surface has a small electrical size, and has good anglestability in a dual polarization mode.

Description

technical field [0001] The invention belongs to the technical field of electromagnetic fields and microwaves, and in particular relates to a three-dimensional frequency selective surface with a double-polarized three-way band. Background technique [0002] In recent years, Frequency Selective Surface (FSS) has been widely studied and applied to various systems, such as radome, antenna sub-reflector, absorber, and electromagnetic shielding. On the one hand, multi-frequency FSS can be used to design multi-frequency antenna reflectors to share the main reflector in different frequency bands; on the other hand, multi-frequency FSS can enhance satellite communication performance. Therefore, with the development of spectrum resources, various multi-frequency There is an increasing demand for three-way band FSS in high-frequency microwave and antenna systems. In practical applications, the three-band FSS is often required to have a flat band-pass response, good frequency selectivi...

AI Technical Summary

Problems solved by technology

However, with the increase of the incident angle, the two kinds of FSS have grating lobe effect in the high frequency band, which affects the filtering performance of FSS.

The team of Professor Shen Zhongxiang from Nanyang Technological University in Singapore first proposed the concept of three-dimensional FSS. Based on the two resonator structures of ladder impedance and uniform impedance, a new type of second-order three-pass three-dimensional FSS was designed using a multilayer printed circuit board, but it only Can work in single-polarization mode, at the same time, the out-of-band introduction does not have any transmission zero, and its frequency selection performance is average

In order to achieve dual polarization, the researchers used circular metal patches of different sizes, and with the help of circular aperture coupling in the middle layer, proposed a dual-polarization, second-order three-pass band FSS, but the transmission zero point cannot be introduced outside the band. , its frequency selective performance needs to be further improved, and at the same time, due to the large electrical size of its unit structure, the angular stability is poor

In addition, the passband ratio of the adjacent passbands of the existing three-pass band FSS is relatively large, which affects its practical application

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