A Millimeter-Wave 8-bits Digital Variable Gain Amplifier in $0.13-\mu \mathrm{m}$ SiGe BiCMOS

This paper introduces the design of a 24∼32 GHz variable gain amplifier (VGA) with a wide gain tuning range for millimeter-wave phased arrays. The VGA is based on a $0.13-\mu\mathrm{m}$ SiGe BiCMOS process and achieved digital gain control using current steering technique. The VGA gain tuning range is from - 16 to 20 dB, which consumes 24 mW with 1.6 V DC power supply. The output P 1dB is 6.7 dBm and NF is 4.7 dB at maximal gain state. The gain flatness is ±0.5 dB across 24∼32 GHz in all 256 states. The chip area is $0.6\times 0.3\text{mm}^{2}$ without testing pads.