Ultrathin Planar HIS Antenna with Beam Steering Capability for K-Band

This paper presents a wideband, ultrathin, planar high impedance surface (HIS) antenna with a beamforming capability which operates at K-band. The HIS antenna is based on a single grounded substrate with a 2D periodic array of dogbone-shaped metallic patches patterned on the top of a ultrathin grounded slab. The structure is designed to operate at 24 GHz with beam steering capability. The structure is fed by a phase-controlled excitation network which adds the ability to steer the beam. The proposed antenna is made of 12 x 6 unit-cells on a very thin substrate (the overall antenna height is around a 100th of the free space wavelength). Simulation results show a maximum broadside gain of 12 dBi and, despite the ultrathin thickness, a 3dB bandwidth of 1.83 GHz with a 2 dBi gain difference in steering the beam from 0 to 45 degrees.