The present invention is a differential transconductance amplifier circuit
that includes matched cross-coupled transconductance elements connected
such that the differential gain of the amplifier is determined by only
passive elements. By virtually eliminating the effects of active elements
on the amplifier gain, the amplifier operates in a very linear manner
over its entire operating range. Power consumption, amplifier noise
level, and dynamic range can be optimized with appropriate selection of
the passive elements that determine amplifier gain.