High-dynamic-range programmable gain amplifier with linear-in-dB and DAC gain control

This paper presents a high dynamic range programmable gain amplifier (PGA) with linear-in-dB and digital to analog converter (DAC) gain control using a BiCMOS process. The proposed PGA is composed of a folded Gilbert variable gain amplifier cell, a DC offset cancellation circuitry, two inductorless fixed gain amplifiers with bandwidth extension, a symmetrical exponential voltage generator, a novel buffer amplifier with active inductive peaking for testing purposes and a 10 bit R-2R DAC. The linear-in-dB and DAC gain control scheme facilitate the analog baseband gain tuning accuracy and stability, which also provides an efficient way for digital baseband automatic gain control. The PGA chip is fabricated using 0.13 mu m SiGe BiCMOS technology. With a power consumption of 80 mA@1.2 V supply voltage, the fabricated circuit exhibits a tunable gain range of - 30-27 dB (DAC linear gain step guaranteed), a 3 dB bandwidth of around 3.5 GHz and a gain resolution of better than 0.07 dB.