Symbolic analysis of microwave circuits - summary

At microwave frequencies lumped element modeling of circuits is not adequate because elements' dimensions are comparable to the signal wavelength. To characterize devices, the most suitable, and from the generator measurement viewpoint the only possible, are scattering S-parameters. S-parameters of time-invariant, linear, networks, containing transmission lines and waveguides, are numerically determined by tools like: Touchstone [1], Linpar [2], Linres [3] or Matpar [4].