Optimal power combining in cascaded active transmit-arrays

Novel configurations of spatial power combiners, which use transmit-arrays to accommodate transistor amplifiers and passive corporate-fed aperture-coupled patch arrays to launch and intercept power, are presented. Theoretical and experimental investigations are performed into optimal spacing between passive 4/spl times/1, 4/spl times/2 and 4/spl times/4-element transmit arrays and the associated launching/intercepting arrays to obtain maximum power combining efficiency. Following this study a 4/spl times/1-element active combiner is developed for which experimental results are presented.