Envelope tracking CMOS power amplifier with high-speed CMOS envelope amplifier for mobile handsets

A high-efficiency CMOS power amplifier (PA) based on envelope tracking (ET) has been reported for a wideband code division multiple access (W-CDMA) and long term evolution (LTE) application. By adopting a high-speed CMOS envelope amplifier with current direction sensing, a 5% improvement in total power-added efficiency (PAE) and a 11 dB decrease in adjacent channel leakage ratio (ACLR) are achieved with a W-CDMA signal. Moreover, the proposed PA achieves a PAE of 25.4% for a 10 MHz LTE signal at an output power (Pout) of 25.6 dBm and a gain of 24 dB.