Transparent and angular stably miniaturized frequency selective surface for tri-band GSM shielding

Abstract

With the widespread application of the global system for mobile communications (GSM), the impact of GSM on human health has become a current research issue. Frequency-selective surface (FSS) shielding is a significant method to address such interference. In this article, a novel geometric design for FSS was proposed to block GSM signals and wireless communication (Wi-Fi) signals, with a cell size of 0.072λ₀×0.072λ₀, a transparency of 70%, and an incidence angle of up to 80° in transverse electric (TE) and transverse magnetic (TM). In addition, a novel methodology with a miniaturized design was introduced to reduce the graphic density and improve the transparency of the FSS. The relationship between the geometric element parameters and the resonant frequency was analyzed and optimized using surface currents and equivalent circuit models. Then, a prototype of the FSS was fabricated, achieving a satisfied shielding effect in a microwave darkroom. This design provided better miniaturization, transparency, and frequency stability than previous designs.