Functional Reconfigurable Integrated Structure of Circularly Polarized Antenna and FSS Absorber

In this article, a novel dual-functional reconfigurable integrated structure is presented. The structure is composed of periodic arrays of four metallic loops, and a hollow Jerusalem cross with resistors etched on 3.3 mm-thick dielectric substrate, lumped resistors, and p-i-n diodes are connected in parallel on the edge of four metallic loops. When p-i-n diodes are switched ON, the designed structure is regarded as a high-gain, circular polarized (CP) antenna array operating within the absorption band. When the p-i-n diodes are switched OFF, the function of the structure is converted into an absorber. In addition, the four patches forming CP are used to increase the bandwidth of axial ratio (AR), and a composite structure is adopted to extend the absorbing band. Finally,
$2\times {2}$
integrated units surrounding absorbing elements are fabricated and measured. The simulated and measured results manifest that the designed integrated structure realizes a high gain of 12.6 dB at 10.8 GHz, an AR from 10 to 12 GHz, and a wide absorption from 7 to 12 GHz.