A Switched-Capacitor-Controlled Digital-Current Modulated Class-E Transmitter

摘要

An envelope elimination and restoration transmitter that comprises a class-E power amplifier (PA) and a digitally controlled current digital-to-analog converter (DAC) modulator are presented. A switched-capacitor DAC is designed to control an open-loop transconductor that operates as a current modulator, modulating the amplitude of the current supplied to a class-E PA. Such a topology allows for increased filtering of the quantization noise that is problematic in most digital PAs (DPA). The system measurements yield a peak output power and system efficiency (SE) of 22.5 dBm and 23.6%, respectively. When applying a local thermal equilibrium signal, the measured error vector magnitude is 3.72% and the adjacent channel leakage ratio is -30.2 dBc, while outputting 18.1 dBm at 10.6% SE.