A 20W Ka-band radial Solid-State Power Amplifier with 20% associated Power-Added Efficiency

This paper presents a high power and high efficiency Ka-band Solid-State Power Amplifier based on the uses of an efficient radial power-combining structure for space applications. This design was validated by the measurement of a 16-way divider/combiner and the characterization of a 16-way High Power Amplifier. Based on the use of 1.3W elementary amplifier modules, the radial HPA delivers an output power higher than 20W with an associated Power-Added Efficiency close to 20% from 35.3GHz to 36.5GHz. The loss of the radial combiner was measured at around 0.3dB. The HPA volume is equivalent to a cylinder of 20cm diameter and 7cm height.