The 2x2 quasi-optical power combiner array at 20 GHz

Investigation of a power combiner made of two FET oscillators for an active array are reported. As an approach by a quasi-optical method, a two-dimensional planar array of strongly coupled oscillators by direct connection through a microstrip line is used. In-phase condition between the oscillators as well as in-phase condition of each radiation wave was accomplished by regulating length of feed microstrip lines. The radiation elements of 1 lambda-slot are embedded in a circuit ground plane. At an operation frequency of 20 GHz, in both H- and E-planes, reasonable sigma radiation patterns were obtained which have good agreement with theoretical patterns.