I work in high frequency RF (10s to 100s of GHz). You can use mixers[0] to down convert higher frequency signals and make measurements at lower frequencies. [0

I work in high frequency RF (10s to 100s of GHz). You can use mixers[0] to down convert higher frequency signals and make measurements at lower frequencies. [0]http://rfic.eecs.berkeley.edu/~niknejad/ee142_fa05lects/pdf/lect15.pdf http://rfic.eecs.berkeley.edu/~niknejad/ee142_fa05lects/pdf/... [pdf]