A millimeter-wave sequential power amplifier

In this paper, we present a millimeter-wave sequential power amplifier (SPA) at the frequency of 26GHz for the first time. The proposed SPA consists of a 3dB power divider, two GaAs power amplifier chips acting as the main and peaking amplifier respectively, and an 8dB output coupler. Measurement results show 6dB back-off efficiency of 18.5% and peak output power of 24.4dBm at 26GHz. The frequency response from 26GHz to 27GHz is also given, and 6dB back-off efficiency better than 18% is achieved from 26GHz to 27GHz.