A Ka-Band Transmitter With 2.7°/0.28 dB Phase/Gain Error and 21.6% PAE Maintaining Stable Performance Across Process Corners

This article presents a Ka-band transmitter for wireless communication that focuses on improving the process corner stability. The proposed transmitter integrates a phase shifter (PS), an attenuator (ATT), a buffer, and a power amplifier (PA). It supports reconfigurable orthogonality from 85.7° to 92.0° in phase shifting, achieving an overall rms phase error of 2.7°. In gain control, the 8-dB attenuation cell eliminates the requirement for compensation capacitors and maintains a stable attenuation performance across different process corners with an overall rms gain error of 0.28 dB. In the PA, improvements on the adaptive bias are made to enhance the performance stability, resulting in a 2.1 dB gain variation and a 0.9 dB OP1dB variation across different process corners. The proposed transmitter realizes an OP1dB of 15 dBm and a maximum PAE of 21.6%. For 64-QAM modulated signals, the PA achieves an average Pout of 8.9 dBm with −26.2 dB EVM at 28 GHz.