Millileter-Wave Power-Combining Amplifier Using A Broadband Waveguide Combiner

A Millimeter-wave power-combining amplifier based on the multi-way rectangular-waveguide power-dividing/combining circuit has been presented and investigated. The equivalent-circuit approach has been used to analyze the passive power-dividing/combining circuits. An eight-device amplifier is designed and measured to validate the power-dividing/combining mechanism using this technique. Both the measured 10-dB return loss bandwidth and the 2-dB insertion loss bandwidth of the passive system are more than 10 GHz. The measured maximum small-signal gain of the millimeter-wave eight-device power amplifier is 22.5 dB at 26.8 GHz with a 3-dB bandwidth of more than 6 GHz, while the input and output return loss of the proposed eight-device power amplifier is around −10 dB from 26 GHz to 36 GHz. The measured maximum output power at 1-dB compression from the power amplifier is 28 dBm at 29.5 GHz.