A low-power low-noise accurate linear-in-dB variable-gain amplifier with 500-MHz bandwidth

S. Otaka, G. Takemura, H. Tanimoto
2000 IEEE Journal of Solid-State Circuits  
A linear-in-dB variable-gain amplifier (VGA) using a pre-distortion circuit to generate the gain-control signal is fabricated in a BiCMOS process with = 20 GHz. The VGA comprises two cascaded stages of signal-summing VGA and has a variable-gain range of over 70 dB. It can operate at up to 500 MHz and dissipates 36 mW from a 3-V supply. A noise figure of below 5 dB and IIP3 of over 38 dBm at 43-dB gain were obtained. The VGA achieved a gain error of less than 2 dB over 70-dB gain range, and it
more » ... cupies approximately 1 mm 2 . The VGA is applicable to future code division multiple access (CDMA) receivers. Index Terms-Code division multiple access (CDMA), gain-compensated circuit, linear-in-dB gain characteristic, temperature-compensation circuit, variable-gain amplifier (VGA).
doi:10.1109/4.890308 fatcat:wbzp44x5jfejrh776kpkxifryu