A variable gain amplifier of such configuration that can yield
continuously and log-linearly variable gains in relation to control
voltage and, at the same time, that does not use an attenuator, an
element which otherwise would entail cause of increased noise. The
amplifier includes a plurality of gm amplifiers connected in parallel
with input signal, exponential multipliers connected respectively to the
gm amplifiers, a control section to vary the multiplication coefficient
of the exponential multipliers according to the external gain control
signal, and an I-V converter circuit to aggregate current output after
multiplication and convert the aggregated current output to voltage. A
continuously variable gain characteristic can be obtained without the use
of an attenuator but by varying multiplication coefficient according to
control voltage.