A 0.7-V Multiclass Digital Doherty Power Amplifier for BLE Applications With 41% Peak DE in 22-nm CMOS

This letter presents a multiclass, asymmetric digital Doherty power amplifier (DDPA) for Bluetooth low energy (BLE) applications, that achieves high efficiency at full-scale as well as at 8.6-dB back-off using a single 0.7-V supply voltage. The proposed DDPA is made of two power-combined switched-capacitor power amplifiers (SCPAs) and uses an on-chip, compact matching network. The DDPA is implemented in a 22-nm bulk CMOS technology, with the main goal of supporting BLE power classes 1.5, 2, and 3 efficiently. The proposed DDPA shows a peak drain efficiency (DE) of 41% at 10.5-dBm full-scale output power, and features an output spectrum compliant with the BLE spectrum emission mask.