The current systems for making phase and amplitude measurements proposed by the large manufactures in the millimeter range of frequencies are restrictive, in that they only reaches 110GHz, and they is very expensive. Using the H.P. 8510 20Ghz vector analyzer we have managed to make an extension which at present reaches frequencies upto 170GHz with 40 dB dynamic range.
M. C. Carter, M. C. Carter,
"A millimeterwave vector analyser", Proc. SPIE 1576, 16th International Conference on Infrared and Millimeter Waves, 15764W (1 October 1991); doi: 10.1117/12.2297889; https://doi.org/10.1117/12.2297889