2. Simplified models

Simplified models can significantly speed up system optimization procedures. For example, a line or guide discontinuity has a transmission and reflection characteristic that can be represented by its distribution matrix [S ]. This can only be accurately calculated using a rigorous electromagnetic method, and must be stored in some way for future use. Indeed, this discontinuity is connected by lines to other elements of a complete system. To analyze the latter over a relatively wide frequency band, we need to determine its distribution matrix [S ] for several frequencies, which can be very time-consuming. The idea is to store the information characterizing the discontinuity so that it can be retrieved quickly.

The first model proposed is, without doubt, the empirical formula, which gives the value of parameters as a function of dimensions, frequency and physical...