Spatial Power Combiner Using an Active Reflect-Array

Spatial power combiners involving planar active microstrip reflect-arrays are investigated. In order to obtain reduced spacing between adjacent active cells dual-feed aperture coupled microstrip patch antennas are used for signal reception and transmission. An X-band 137-element active reflect-array illuminated by a small horn antenna and radiating in boresight direction is presented as one design example. In order to investigate free-space losses of this type of combiner, a passive reflect-array illuminated by a dual polarised sub-array is considered as the second design example. A full-wave analysis is applied to determine insertions losses for different illumination conditions of this structure.