Narrowband bandpass frequency selective surface

Abstract

The invention discloses a narrowband bandpass frequency selective surface. The frequency selective surface is formed by periodically arranging a plurality of same unit structures, and each unit structure comprises a square metal cylinder and a square dielectric block. Two identical Jerusalem metal cross-shaped part are engraved in the upper surface and the lower surface of the square dielectric block respectively, and the middle layer is a square metal plate with four identical rectangular apertures. The upper surface resonance structure and the lower surface resonance structure of the unit structure generate an electromagnetic coupling effect through the rectangular aperture of the middle layer, two transmission poles are generated, and a flat passband is formed. Meanwhile, two transmission zeros are introduced out of the right side of the passband, so that the filter has high frequency selectivity and wide out-of-band rejection. Meanwhile, the frequency selective surface has good angle stability 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 narrowband bandpass frequency selective surface. Background technique [0002] Frequency Selective Surface (FSS), as a kind of spatial filter, has been widely concerned by researchers in recent years. Due to its unique spatial filtering characteristics, it is often used in radar radomes, absorbing materials, and antenna sub-reflectors. In narrowband communication application scenarios, it is necessary to design a bandpass FSS with narrowband characteristics. [0003] Traditional two-dimensional FSS is often limited in achieving high performance indicators. For example, limited resonance modes cannot introduce more transmission zeros and poles, the working bandwidth of single-layer FSS is limited, and the thickness and electrical size of multi-layer FSS increase. Waiting is not enough. Later, researchers proposed the concept of three-...

AI Technical Summary

Problems solved by technology

The team of Professor Shen Zhongxiang from Nanyang Technological University in Singapore first proposed the concept of 3D FSS. They designed a series of bandpass 3D FSS based on the shielded microstrip line structure. The above problems have been effectively improved, but these structures can only work in single polarization mode. limit their practical application

Later, some researchers proposed a dual-polarization bandpass three-dimensional FSS based on the square coaxial waveguide structure. Due to the symmetrical design of its unit structure, it is easy to achieve dual-polarization performance, but its weight is relatively large, the assembly is complicated, and the cost is high.

Some researchers have also realized a bandpass three-dimensional FSS with broadband characteristics based on a metal plate loaded dielectric resonator with via holes, with the help of electromagnetic coupling, but there are no transmission zeros on both sides of the passband, and its frequency selection performance and out-of-band suppression performance are average.

Images