Decade bandwidth high efficiency GaN HEMT power amplifier designed with resistive harmonic loading

The use of resistive loading at higher harmonics in wideband power amplifier design is proposed. Although the theoretical efficiency of such operation is lower than other classes the significantly simplified load network design potentially allows for multi-octave realizations. A decade bandwidth (0.4–4.1 GHz) GaN HEMT power amplifier was thereby designed, delivering more than 40 dBm output power with 10–15 dB gain and 40–62% drain efficiency. Linearized modulated signal amplification was then successfully demonstrated at multiple frequencies (0.9 to 3.5 GHz), using various downlink signals (LTE, WCDMA, WiMAX), with resulting ACLR lower than −46 dBc.