Scattering Matrix for Waveguide Components
The analysis of networks or devices at low frequencies commonly uses circuit parameters such as Z parameters, Y parameters, and ABCD parameters. These parameters are derived based on terminal voltage and current measurements. They require the application of short- and open-circuit terminations for evaluation. A brief description of these parameters is given in Section 7.8.
However, it is very difficult to measure voltages and currents at microwave frequencies because of the following reasons:
- They are distributed values and vary with their position in microwave structures.
- Active devices become unstable when they are terminated with open or short circuits at high frequencies.