A dual-polarized switchable microwave absorber

This paper describes a new design of dual-polarized circuit analog absorber, which is a two-dimensional periodic array of unit cells. Each unit cell consists of a top capacitive sheet, PIN diodes connected with microstrip lines on the middle layer, and a conducting ground plane. By changing the biasing state of PIN diodes, two switchable operating bandwidths can be achieved. With proper selection of the component values, this structure can realize wide bandwidths for the two states under both TE and TM incidences. A design example is provided to demonstrate the design principle and switchable absorption.