A Miniaturized Quad-Stopband Frequency Selective Surface with Convoluted and Interdigitated Stripe Based on Equivalent Circuit Model Analysis.

Jian Dong,Yan Ma,Jinjun Mo,Zhuangzhuang Li

doi:10.3390/mi12091027

Abstract

This paper presents a miniaturized frequency selective surface (FSS) based on the convoluted and interdigitated stripe with multiple narrow passbands/wide stopbands in the L-/S-/C-/X-/Ku-/K-band. By using the convoluted and interdigitated stripe, the coupling inside is well controlled, so that the spatial efficiency is maximized to provide a high miniaturization. An equivalent circuit model is presented to reveal the working mechanism of the proposed FSS. The proposed structure forms four transmission band rejections of 3 dB in 1–6.65 GHz, 8.35–16.9 GHz, 18.0–24 GHz, and 24.50–27.84 GHz. The size of the unit cell is 0.09λ0 × 0.09λ0, where λ0 is the wavelength of the first resonance frequency. The proposed FSS has a good angle stability and polarization stability in a scanning range up to 60°. For verification, an FSS prototype has been fabricated and measured. The measured results were in agreement with the simulated results. The proposed FSS can be used in practical applications such as radomes, antenna reflectors, and spatial filters.

Highlights

A frequency selective surface (FSS) is composed of periodically arranged patch-type units or aperture-type units and dielectric substrates, with spatial filtering characteristics
When FSS is irradiated by the incident wave, a unit cell of FSS can be regarded as a resonant circuit
For bandpass FSS, the capacitors distributed in the FSS unit can be divided into intercapacitor (Cinter ) and intracapacitor (Cintra ), where Cinter is the capacitance inside the element and Cintra is the capacitance between the elements

Summary

Introduction

A frequency selective surface (FSS) is composed of periodically arranged patch-type units or aperture-type units and dielectric substrates, with spatial filtering characteristics. Vertical vias are loaded into the crossed dipoles to increase the capacitance and inductance in the highfrequency band and reduce the corresponding resonance frequency. [17] proposed a method of designing a dual-band miniaturized-element frequency selective surface (MEFSS). The proposed structure consists of grids and complementary capacitor patches arranged periodically in two dimensions, separated by a dielectric substrate. This structure is based on an inductively coupled MEFSS, which uses a capacitively loaded dielectric pad as its main resonator. For TE and TM incident polarization, the incident angle is relatively stable in the range of 45◦

Methods

Findings

Discussion

Conclusion