The use of various harmonic orders permits an unprecedented frequency coverage, from X band to submillimeter, in a single apparatus, with an excellent dynamic range. The characterization of components, antennas and dielectrics, as well as solid state physics studies, are among the many possible applications.
P. Goy, P. Goy,
"8-1000 GHz vector network analyzer", Proc. SPIE 1514, 15th International Conference on Infrared and Millimeter Waves, 15140X (1 December 1990); doi: 10.1117/12.2301443; https://doi.org/10.1117/12.2301443