SNP model

Bilateral type model: ie it considers load and source impedance variations.

Model with high frequency linear memory: i.e. that it considers the frequency dispersion caused in the operating bandwidth of the devices.

Mathematical description.

In the general case of quadripol, the general equation of the model is the following :

This expression can be genralized to any multi-port device :

Each Sij kernel can be seen as a genral f function which can be approximate. The extraction process consists of calculating the poles and residues of the parameter S11 associated with the S1P. The technique used is the VectorFitting (VF) method which allows the efficient rational approximation of a function f (s) defined from frequency samples of the system:

Where Am are the poles and Cm the residues.

For more details we can consult the references:

Rational approximation of frequency domain responses by vector flltlng. Bjørn Gustavsenand Adam Semlyen .

Improving the Pole Relocating Properties of Vector Fitting. Bjørn Gustavsen.

Identification principle.

The idetification principle is done thanks Calibrated Sparameters measurement . These measurements are generally perform with standard VNA equipment.

Validity domain.

This linear model of bilateral type works in envelope time, according to the choice made on the simulation mode, it considers or not the transient regime. The number of access is 2.