Spatial power combining and phased-array behavior of circularly polarized active patch antennas

Design of circularly polarized active antennas of dual-fed square patch typ e is given, and spatial power combining and phased array operation of the a ntennas have been successfully achieved. In a phased array experiment of th e arrays with two and three active antennas by the method of varying their free-running oscillation frequencies, we obtained the scan angles from -12 degrees to + 13 degrees and those from -13 degrees to + 13 degrees, respect ively and good axial ratios together with high spatial power-combining effi ciencies.