A 7.9-mW 5.6-GHz Digitally Controlled Variable Gain Amplifier With Linearization

This paper presents the design and validation of a compact high-performance digitally controlled variable-gain amplifier (DVGA). By using MOS switches and a linearizer, the designed DVGA demonstrates high linearity and gain flatness over a wide gain control range. The 6-bit DVGA is designed in a commercial 0.18-μm SiGe BiCMOS technology achieving a variable gain range from -16.5 to +6.5 dB, a 3-dB bandwidth from dc to 5.6 GHz, a ± 0.75-dB gain flatness from dc to 4 GHz, both input and output return loss greater than 15 dB, consuming 7.9 mW over the entire gain control range, and has a core circuit area of 170μm×60μm.