Abstract
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-mu m 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 170 mu m x 60 mu m.