A miniaturised frequency selective rasorber with wide transmission band

Abstract This paper demonstrates a miniaturised frequency selective rasorber (FSR) that incorporates meander cross‐rings to realise a wide transmission band. The FSR comprises a resistive layer and a bandpass frequency selective surface (FSS), which are separated by an air layer. The resistive layer is constructed by employing meander cross‐rings equipped with lumped resistances, where the inner arms of cross‐rings are bent to obtain a parallel resonant circuit with large inductances and small capacitances to achieve broadband transmission at high frequencies. The bandpass FSS is implemented using a triple‐layer metallic structure, where two identical square ring layers are coupled through a central metal grid layer to form the transmission band. The measured results indicate that the absorption band with absorptance exceeding 90% is from 3.5 to 9.4 GHz, and the passband exhibiting insertion loss of less than 1 dB spans from 11.92 to 17.98 GHz with a 40.5% relative bandwidth, which matches well with simulated ones. This FSR has the characteristics of simple structure and high performance, which provides a novel concept of stealth applications.