Design and Analysis of Printed Lossy Capacitive Surface-Based Ultrawideband Low-Profile Absorber

In this communication, an ultrawideband low-profile absorber is designed using printed lossy capacitive surface on a ground-backed substrate. Simple guidelines are proposed to design the absorber using the impedance analysis of its equivalent circuit model. The 10 dB reflection reduction for 120% fractional bandwidth from 3 to 12 GHz is achieved by generating three resonances using a single element in the unit cell. The thickness at the lowest cutoff frequency of the proposed absorber is thus obtained as 0.080 lambda(L)(lambda(L) is the wavelength at the lowest cutoff frequency). It is shown that the proposed absorber is polarization insensitive and capable of reducing radar cross section for all the reflection angles in both monostatic and bistatic scenarios. To manufacture the absorber, commercially available low-cost resistive ink, Y-shield HSF 74 is used. The measurement results are provided to validate both the full-wave and circuit simulated results.