A Compact Ka-band 35W Power-Combining Amplifier

This paper presents the development of a 35W Ka-band Power-combining Solid-states Power Amplifier (SSPA) with 80% power combining efficiency (PAE). The amplifier consists of an eight-way rectangular spatial waveguide power splitter/combiner and eight power amplifier MMIC chips, these chips were fed by a novel Horizon-Vertical bias supply scheme, which effectively decrease the size of the module. The eight-way power splitter/combiner was combined with three-stage waveguide E-plane T-junction and eight ceramic microstrip probes designed for matching rectangular waveguide with MMICs. Moreover, the SSPA module was fabricated and continuous-wave output saturated power and power-added efficiency (PAE) measurements are performed, which indicated a good performance of the amplifier.