Patent ID: 7518353

Claim:
The vector network analysis system comprising: an offset stimulus source providing first and second stimulus signals, the first stimulus signal being offset from the second stimulus signal in one or both of frequency and time-varying phase; and a vector network analyzer having at least four ports, the offset stimulus source configured to present the first and second stimulus signals at two of the ports of the vector network analyzer, wherein the vector network analyzer is configured to measure performance parameters at two ports of the vector network analyzer, wherein the offset stimulus source comprises: a first frequency source producing the first stimulus signal of the plurality; a second frequency source producing the second stimulus signal of the plurality that is offset from the first stimulus signal, the second frequency source comprising a summer connected between an input and an output of the second frequency source, a reference signal source connected between an input of the first frequency source and the input of the second frequency source; and a phase offset controller connected between an output of the first frequency source and the output of the second frequency source, the phase offset controller having an output connected to an input of the summer.