Design and study miniaturized-element wideband frequency selective surface

Abstract

In this letter, we propose a miniaturized-element frequency selective surface (MEFSS) by using the LC coupling mechanisms between three metal arrays cascade by two layers substrates, so this unit cell size will not be restricted by wavelength. In order to improve resonance stability performance with respect to different polarizations and incidence angles, according to the traditional FSS hexagonal element, we create periodic elements of capacitive surface and inductive surface with hexagonal shape and hexagonal element array is in the form of equilateral triangle. An equivalent circuit model for the operating principle of MEFSS was proposed. On the basis of the transmission lines theory, the approximation formulas of the inductance and capacitance were provided. In order to the optimal parameters of wideband performance, the grid array and the effects of the parameteristice of hexagonal element on the frequency response characteristics of MEFSS are simulated using the full-wave analysis software. With PCB technology, the hexagonal metal arrays between F4B-2 are produced and a prototype MEFSS using freedom space method is examined. Both simulated and measured results obtained show that the MEFSS constructed by using hexagonal element array has much better frequency resonance stability performance with respect to different polarizations and 60° incidence angles, and the −0.5 dB bandwidth reaches up to 5 GHz. We present a theoretical and experimental reference of MEFSS for the applications in large-angle incidence curved streamlined radome.