Читать книгу Handbook of Microwave Component Measurements - Joel P. Dunsmore - Страница 138

It is important to note that all the conversions described in the previous sections are valid only for the case of Z₀₁ = Z₀₂ = Z₀ and that Z₀ be pure‐real. The transformations for cases where the port impedances are not equal, and not real, have been computed and are available in papers by Marks and Williams (1992) and with using somewhat different wave definitions, by D.A. Frickey (1994). While the case of complex termination impedances is unusual, the case for differing reference impedances on ports is more common. Since the network elements do not change when reference impedance of the system is changed, Y‐, Z‐, and H‐related parameters also do not change with reference impedance. S‐ and T‐ parameter values do change, and thus it is critical to know the reference impedance for each case.