Manufacturable ultra-thin resistive FSS for challenging EM mobile environments

This paper reports on recent developments in the manufacture and measured electromagnetic (EM) performance of a new class of thin microwave absorbers based on metal backed resistively loaded Frequency Selective Surfaces (FSS). Ink jet printing technology is shown to be a viable method for creating patterned FSS elements very close to the desired resistance values. This is demonstrated by comparing simulated and measured reflectivity plots for an ink jet and a stencil printed polarisation independent absorber that is designed to work in the frequency range 7.1–24 GHz. Numerical simulations show that thin FSS absorbers provide radar backscatter suppression, not only in the far field of the illuminating antenna, but also when the EM source is placed very close to the surface of the periodic array. This technology can therefore provide a solution for enhancing the performance of wireless sensors placed close to lossy loads such as the human body.