ABSTRACT

The vector network analyzer (VNA) is the most important instrument in microwave measurements today. Its primary function is the measurement of S-parameters (remember that these are defined for linear time-invariant systems). Starting from the rudimentary setup using a directional coupler and some power sensors described in Chapter 3, this instrument has evolved into the workhorse of any microwave laboratory, and is today moving into measurement of nonlinear properties of components, and the frequency of operation today entering the THz region.