Aliasing-Compensated Polar PWM Transmitter

This brief presents a novel pulse-width modulation (PWM) transmitter architecture that compensates for aliasing distortion by combining PWM and outphasing. The proposed transmitter can use either switch-mode power amplifiers (PAs) or linear PAs at peak power, ensuring maximum efficiency. The transmitter shows better linearity, improved spectral performance, and increased dynamic range compared to other polar PWM transmitters (PPWMTs) as it does not suffer from AM–AM distortion of the PAs and aliasing distortion due to digital PWM. Measurement results show that the proposed architecture achieves an improvement of 8 and 4 dB in the dynamic range compared to the digital PPWMT and the aliasing-free PWM transmitter (AF-PWMT), respectively. The proposed architecture also shows better efficiency compared to the AF-PWMT.