DESIGN OF SUBWAVELENGTH TUNABLE AND STEERABLE FABRY-PEROT/LEAKY WAVE ANTENNAS

The design of a thin tunable and steerable Fabry-Perot antenna is presented. The subwavelength structure is analyzed both by an efficient transmission line model and by full-wave simulations. The tunable antenna consists of a low profile resonant cavity made up of a Partially Reflecting Surface (PRS) placed in close proximity of a tunable high-impedance surface. The active ground plane is synthesized by loading the high-impedance surface with varactor diodes. Such design allows both tuning the high-gain operational frequency and obtaining a beam steering/shaping for each resonant frequency. The transmission line model here presented includes averaged analytical expressions for modelling the tunable high-impedance surface and the frequency selective surfaces. All the theoretical speculations are verified by full-wave simulations on a finite size structure.