S-Parameter Simulations > S-Params., Stability, and Group Delay vs. Frequency and Input Power

Description

This schematic simulates the large-signal S-parameters of a device, versus frequency and input power. The stability factor, K, is computed from these S-parameters, using the standard formula found in textbooks. This simulation setup differs from the LSSP controller in that small-signal mixer mode is used to inject a small signal at the output of the device, while the input is being driven by a large signal source. This gives a much more realistic simulation of S12 and S22.

Needed to Use Schematic

Nonlinear model, or an amplifier with nonlinear device models

Main Schematic Settings

Ranges over which to sweep the input signal frequency and power

Data Display Outputs

Stab_vs_freq_pwr.dds, "Stability and S-Parameter Plots" page:

• S-Parameters versus input frequency and input power
• Stability factor, K, versus input frequency and input power

Stab_vs_freq_pwr.dds, "Group Delay" page:

• Group delay versus frequency, with the input power selected by moving a marker

Schematic Name

Stab_vs_freq_pwr

Data Display Name

Stab_vs_freq_pwr.dds

Note

The stability factor is only computed at the frequency of the input signal. The stability factors at higher and lower frequencies are not computed.