Circuit-Based Dual-Resonance Energy Selective Surface

A design method for the circuit-based dual-resonance energy selective surface (ESS) is proposed. The generalized structure of the ESS consists of two modules: a band-stop frequency selection surface (FSS) and an LD (inductor and diode) parallel circuit. They can generate band-stop and band-pass resonance under high- and low-power signal incidence, respectively. By optimizing two resonant circuits separately, high shielding efficiency and low insertion loss can be realized simultaneously. The design principle is revealed through the equivalent circuit model. To validate the proposed method, a miniaturized dual-resonance ESS with a unit cell size of 0.08λ ₀ × 0.08λ ₀ and thickness of 0.0046λ ₀ is designed. The results show that it has an insertion loss of 0.66 dB and a shielding effectiveness of 31.27 dB at 1.7 GHz. In addition, its ultrathin design and stable angular performance make it promising for various prospects in EM protection and radome design.