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].