  High-quality microwave amplifiers and notch-filters can be made from
microwave optomechanical systems in which a mechanical resonator is coupled to
a microwave cavity by radiation pressure. These amplifiers and filters rely on
optomechanically induced transparency (OMIT) and absorption (OMIA),
respectively. Such devices can amplify microwave signals with large,
controllable gain, high dynamic range and very low noise. Furthermore,
extremely narrowband filters can be constructed with this technique. We briefly
review previous measurements of microwave OMIT and OMIA before reporting our
own measurements of these phenomena, which cover a larger parameter space than
has been explored in previous works. In particular, we vary probe frequency,
pump frequency, pumping scheme (red or blue), probe power, pump power and
temperature. We find excellent agreement between our measurements and the
predictions of input/output theory, thereby guiding further development of
microwave devices based on nanomechanics.
