Transmission line coupled active microstrip antennas for phased arrays

An effective transmission line coupling network for spatial power combining and beam scanning purposes is reported. The harmful effect of radiative coupling is eliminated using a modified version of this network for peripheral elements. A technique to control the inter-element phase differences of planar arrays was also developed. Experiments on 1/spl times/4 and 2/spl times/2 oscillator arrays using the proposed coupling network agrees well with the theory.