Integrated planar spatial power combiner

A simple low-loss integrated planar spatial power-combining architecture is proposed and studied in this paper. The power-combining structure is realized by transition between a simple oversized microstrip line and parallel multiport planar microstrip lines. The power combiner was simulated with parametric analysis and a working prototype at 25-31 GHz is designed and fabricated with four amplifier units. Measured results show a good agreement with simulated ones and a combining efficiency of 79.5% is achieved at 25 GHz.