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
- 1
- 2
- 3(1,2)
Kurokawa, Kaneyuki “Power waves and the scattering matrix”, IEEE Transactions on Microwave Theory and Techniques, vol.13, iss.2, pp. 194–202, March 1965.
- 4(1,2)
Marks, R. B. and Williams, D. F. “A general waveguide circuit theory”, Journal of Research of National Institute of Standard and Technology, vol.97, iss.5, pp. 533–562, 1992.