Design of a Single-Layer Circuit Analog Absorber Using Double-Circular-Loop Array via the Equivalent Circuit Model

A broadband Circuit Analogue (CA) absorber using double-circular-loop array is investigated in this paper. A simple equivalent circuit model is presented to accurately analyze this CA absorber. The circuit simulation of the proposed model agrees well with full-wave simulations. Optimization based on the equivalent circuit model, is applied to design a single-layer circuit analogue absorber using double-circular-loop array. Simple guidelines for designing the CA absorber are then formulated. It is demonstrated that the fractional bandwidth of 125.7% is realized for at least 10 dB reflectivity reduction with angular stability to 40? for both TM and TE modes. The total thickness of the absorber design is 0.093?L at the lowest operating frequency.