Electronically Steerable 1-D Fabry-Perot Leaky-Wave Antenna Employing a Tunable High Impedance Surface

A novel fixed-frequency electronically-steerable one-dimensional (1-D) leaky-wave antenna is presented. The antenna is based on a parallel-plate waveguide loaded with a planar partially reflective surface and a tunable high impedance surface (HIS), which creates a 1-D Fabry-Perot leaky-waveguide. The tunable HIS consists of printed patches loaded with varactor diodes that allow the electronic tuning of the cavity resonance condition. Using a simple Transverse Equivalent Network, it is theoretically shown how the variation of the varactors\´ junction capacitance allows the scanning of the antenna pointing angle from broadside towards the endfire direction at a fixed frequency. Experimental results of an antenna prototype operating at 5.6 GHz are reported, demonstrating that the new reconfigurable leaky-wave antenna can provide electronic beam scanning in an angular range from 9 $^{\circ}$ to 30 $^{\circ}$