High efficiency 80W X-band power amplifier using coaxial waveguide spatial power combining technique

As the commercially available microwave monolithic integrated circuit (MMIC) amplifiers improve in output power and bandwidth a compact platform to combine a large number of these MMICs, becomes very desirable. A reduced size version of a coaxial waveguide combiner structure using an antipodal finline antenna array is investigated. The reduced size coaxial waveguide combiner structure is used to demonstrate an 80 Watt power amplifier at X-Band by combining 16, 6 Watt MMIC devices and the scalability of the overall combiner platform. Around 30% efficiency has been achieved for most of the band.