A RF switch can be used in a wide frequency range and can be manufactured
at a low cost. The RF switch changes a signal passing through a waveguide
with a variable device that is switchable between the first state in
which the variable device has a high resistance and the second state in
which the variable device has a low resistance, depending on the
direction in which current flows through the variable device. The RF
switch includes a high-frequency transmission circuit including the
waveguide and at least one variable device, a driver circuit including at
least one variable device, and a signal circuit for changing current
supplied to the variable devices of the high-frequency transmission
circuit and the driver circuit for switching between the first and second
states of the variable devices. The variable devices are disposed such
that the variable device of the high-frequency transmission circuit and
the variable device of the driver circuit are in different states as
viewed from the junction between the drive circuit and the high-frequency
transmission circuit.