Generalized expressions for characterizing a linear multiport circuit coupled with external fields

The outputs of a linear multiport circuit immersed in external fields are analyzed using the S-parameters in frequency and time domains. It is suggested that the matched output voltage is a proper and convenient parameter for characterizing the circuit coupled with external fields, since it can be measured easily in a higher frequency range than a few hundred megahertz. The output voltages of the circuit terminated with loads of arbitrary impedance are calculated from measured values of the matched output voltages, the S-parameters of the circuit, and the reflection coefficients of the loads. Related formulas are derived for the characterization