High-dynamic-range variable gain amplifier with temperature compensation and linear-in-decibel gain control

A novel intermediate-frequency variable-gain amplifier for wideband code-division multiple access transmitters is presented. The circuit includes a compensation technique for parasitic coupling, which allows a high dynamic range of 85 dB to be attained while using a single variable-gain stage. Temperature compensation and decibel-linear characteristic are achieved by means of a control circuit providing a lower than +-1.5 dB gain error over full temperature and gain ranges.