This letter proposes a Sub-GHz digital polar power amplifier circuit, which is intrinsically linear and power efficient. The architecture is based on a 1-bit delta–sigma modulator (DSM) to achieve ...

Moreover, the AM-PM cross distortion is filtered by the loop itself. The chip operates from a 0.9-V supply at 5.5 GHz with 2.5 MHz BW (1024 QAM) with average 1.1-dBm output power and total power ...