S-parameters (from the English. Scattering - scattering) - the elements of the scattering matrix of a multipole , usually describing a radio device.
Method of analyzing linear microwave devices using S-parameters
Various types of microwave devices can be described using incident and reflected waves that propagate in the transmission lines connected to them. The relationship between these waves is described by a wave scattering matrix or a matrix of S-parameters.
The properties of a multipole are described using N equations linking the complex amplitudes of the incident and reflected waves.
a 1 , a 2 ... a N - the complex amplitudes of the waves entering the multi-terminal (incident waves);
b 1 b 2 ... b N - the complex amplitudes of the waves emerging from the multipole (reflected waves);
S kk ( k = 1,2, ... n) is the reflection coefficients for the corresponding inputs of a multipole when connecting matched loads equal to R 0 to all other inputs;
- transfer coefficients of the amplitudes of voltage waves from the m-th line to the k-th when connecting matched loads equal to R 0 to all other inputs;