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

This paper presents a multi-class, asymmetric digital Doherty power amplifier (DDPA) for 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.