A lowpass biquad VGA filter

摘要

A biquad gain stage, as well as a Variable Gain Amplifier is disclosed. The biquad gain stage comprises a plurality of transistors as well as conductances, and capacitances, as well as current sources. The resulting variable gain amplifier comprising a plurality of biquad gain stage cascaded in series allows to filter large unwanted blockers and to amplify a small wide-band signal. Both the gain and the filtering are distributed along a signal chain comprising a series of low-noise, high-Q biquad gain stages, each with limited current consumption and low component ratios.