A satellite broadcasting receiver (LNB) receiving signal radio waves from broadcasting
satellites is provided with a low noise amplifier (LNA) amplifying a received signal,
and a frequency converting circuit converting an output from the LNA to an intermediate
frequency signal for output. The LNA includes four amplifiers in the first stage
respectively amplifying four types of different received signals. A power supply
control circuit sets a current flowing through one of four amplifiers at a prescribed
value and sets currents flowing through all the other amplifiers at 0. Thus, the
output from only one amplifier is supplied to the amplifier in the second stage
for amplification and further applied to the frequency converting circuit. Accordingly,
the amplifiers in the first stage do not simultaneously consume currents, and a
switching circuit is not necessary.