Can instrumentation amplifiers be useful in mixer design? Or other microwave designs?

I just searched for new OpAmps and found this new word for me "Instrumentation amplifier". Are they used in microwave designs? I guess mixers or maybe power meters, as instrumentation amplifiers "particularly suitable for use in measurement and test equipment" (wikipedia)..

If you continue reading, you'll surely find application circuits that demonstrates typical usage of instrumentation amplifiers.

They have mostly bandwidths below 1 MHz and are rarely suitable for RF circuits. Amplifying DC quantities in a RF instrument, e.g. a dectctor voltage can be a reasonable application.

Besides instrumentation amplifiers, there's also a category of fully differential amplifiers, some with > GHz bandwidth which may well serve RF applications.

Mixer is nonlinear device while amplifier is linear.
http://en.wikipedia.org/wiki/Frequency_mixer
http://en.wikipedia.org/wiki/Amplifier

Term mixer is also used to describe adding two or more signals usually in audio. That is done with OPAs.