Design of a wide-angle, polarization-insensitive, dual-band metamaterial-inspired absorber with the aid of equivalent circuit model

We present the design of a wide-angle, polarization-insensitive, dual-band, low-profile metamaterial-inspired absorber for operation at two wireless local area network channels, related to 2.45 and 5 GHz industrial, scientific and medical frequencies. The design synthesis methodology involves equivalent circuit model calculations with the use of analytical expressions of capacitive and inductive elements prior to full-wave electromagnetic optimization, for easily acquiring of very high absorption conditions at the targeted frequencies. The unit cell of the metamaterial-inspired absorber consists of a joint metallic Jerusalem cross resonator with interdigital capacitors and a tetra-arrow resonator printed on top of a grounded 1-mm-thick lossy FR-4 substrate. The proposed absorber shows almost unity absorptivity at the targeted frequencies and a robust absorption characteristic under changes in incidence angle and polarization. The proposed structure can be used for protection of the systems from electromagnetic interference with existing wireless local area network frequencies.