Average Power Tracking Power Amplifier with Multilevel Supply Voltage for Wi-Fi Applications

An average power tracking (APT) power amplifier (PA) using a multilevel supply voltage DC-DC converter is presented for IEEE Wi-Fi applications. The PA operates in high, middle, and low average output power regions by setting the DCDC converter output to 4 V, 3 V and 2 V, respectively. Power added efficiency (PAE) of the APT PA is significantly improved by reducing DC power consumption in low and middle output power regions. The APT PA aided by predistortion can further improve PAE when the PA operates in less back-off from 1-dB compression point (PldB) without causing significant nonlinearity distortion. For a 5 GHz 64-QAM OFDM signal with 20 MHz bandwidth and 9. SdB PAPR, the APT PA with a 2.0 V voltage supply delivers a PAE of 25% at an average output power of about 10 dBm, which is 15% higher than that of the conventional PA with a fixed voltage supply of 4 V at the same average output power.