Two-Dimensional Beam Steering Active Lens With Simple Grid Bias Lines at 19 GHz

Abstract

This paper presents two-dimensional (2D) beam-steering of an active lens with simple grid bias lines at 19 GHz. In general, 2D beamforming in azimuth and elevation planes requires one-to-one unit cell control for a 2D phase distribution on a planar lens. In this work, the 2D phase distribution is achieved with only M vertical and N horizontal bias lines for MxN unit cells. The active unit cell is based on an I-shaped resonator and includes a varactor diode associated with two bias lines shared by neighboring unit cells. The five-layer unit cell achieves a phase range of more than 360 degrees. The 32x32 unit-cell-stacked prototype demonstrates pencil beam scanning up to +/- 40 degrees in the E- and H-planes with a 15.8% 3-dB bandwidth, a 17.5-dBi broadside gain, and low power consumption of 5.2 mu W per beam switching. The 2D beam-steering for (theta(0), phi(0)) = (30 degrees, 45 degrees) is verified through simulation and experimental results at 19 GHz.