A 60-GHz variable gain amplifier with low phase and OP1dB variation

Abstract

This article presents a 60 GHz variable gain amplifier (VGA) with a low phase and output 1-dB gain compression point (OP1dB) variation for phased-array applications. The VGA employs a two-stage modified current-steering cascode. Implemented in 0.18-mu m SiGe BiCMOS technology, the VGA has a gain control range of 20.4 dB with a maximum gain of 17.7 dB at 60 GHz. The OP1dB variation is only 2.3 dB for all gain states at 60 GHz with a DC power consumption of 50 mW, and the measured phase variation is less than 4.8 degrees at 57 to 66 GHz.