US Patent 7719359 Low noise variable gain amplifier

A variable gain amplifier may include a gain block, a voltage control block, and a unity gain buffer block. The gain block may include a plurality of amplifiers having a fixed gain. The voltage control block is coupled to the output of the gain block. Moreover, the voltage control block controls, based on control voltages applied to the plurality of amplifiers having fixed gain, current output by the plurality of amplifiers. The unity gain buffer amplifier is coupled to receive the current output by the plurality of amplifiers of the voltage control block. The unity gain buffer amplifier provides an output signal of the variable gain amplifier. Related systems, methods, and articles are also described.