A CMOS Microwave Phase-Shifter With High IP1dB Employing Novel Folded VGA

An active analog phase-shifter utilizing the vector-sum method for the frequency band of 7.5–8.5 GHz is designed and verified in this letter. A new variable gain amplifier (VGA) is proposed which improves the overall input 1-dB compression point of the phase-shifter. The phase-shifter is fabricated in a 180-nm TSMC CMOS process and provides full 360° phase tuning range while consuming only 18.9-mW core power and 0.77-mm2 area excluding pads. The proposed phase-shifter has the lowest input-referred 1-dB compression point (IP1dB) of around +2.5 dBm for various phase-shift settings at the center frequency of 8 GHz, which is very high compared to most of the CMOS vector-sum phase-shifters reported for the chosen bandwidth in the literature so far. In addition, the maximum output phase deviation is only around −1.68° to +2.2° within the targeted bandwidth for a wide input-power range of −25 to +2.5 dBm.