A 0.13 μm CMOS 90 dB variable gain pre-power amplifier using robust linear-in-dB attenuator

A 0.13um CMOS pre-power amplifier with 90dB gain range is fabricated. The pre-power amplifier consists of 4 variable attenuators and 3 fixed gain amplifiers, where the proposed attenuator suppresses the attenuation variation due to Vth variation. The pre-power amplifier outputs +4dBm with 75mW and −80dBm with 65mW. The ACPR is −48dBc and the EVM is less than 1.0% at Pout = +4dBm. The attenuation variation of less than +/−5dB is achieved.