skrf.network.s2z¶

skrf.network.s2z(s, z0=50, s_def='power')[source]¶

Convert scattering parameters [1] to impedance parameters [2].

For power-waves, Eq.(19) from [3]:

\[Z = F^{-1} (1 - S)^{-1} (S G + G^*) F\]

where \(G = diag([Z_0])\) and \(F = diag([1/2\sqrt{|Re(Z_0)|}])\)

For pseudo-waves, Eq.(74) from [4]:

\[Z = (1 - U^{-1} S U)^{-1} (1 + U^{-1} S U) G\]

where \(U = \sqrt{Re(Z_0)}/|Z_0|\)

Parameters:

s (complex array-like) – scattering parameters
z0 (complex array-like or number) – port impedances.
s_def (str -> s_def : can be: 'power', 'pseudo' or 'traveling') – Scattering parameter definition : ‘power’ for power-waves definition [3], ‘pseudo’ for pseudo-waves definition [4]. ‘traveling’ corresponds to the initial implementation. Default is ‘power’.

Returns:

z – impedance parameters

Return type:

complex array-like

References