S-Parameter Simulations > Feedback Network Optimization to Attain Stability

Description

This schematic optimizes component values in input, output, and feedback stabilization networks, to stabilize a 2-port network, minimize the minimum noise figure, and maximize gain (dB(S21).) You may delete components or modify the structure of the stabilization networks.

Needed to Use Schematic

Any linear or nonlinear model, including measured S-parameters

Main Schematic Settings

Type of optimization algorithm (gradient, random, genetic, etc.), goal weighting, goal values, and frequency ranges over which noise figure and gain goals will be evaluated.

Data Display Outputs

• Geometrically-derived source and load stability factors
• Gain, dB(S21)
• Minimum noise figure
• Values of optimized components

Schematic Name

Gain_and_Stab_opt

Data display name

Gain_and_Stab_opt.dds

Note

The optimization results may vary substantially, depending on the type of optimization algorithm used (set on the Nominal Optimization controller) and on the goals. Noise figure and gain have been included as optimization goals. Otherwise, the optimizer might find a stable network, but with poor performance as an amplifier. The feedback network topology might be modified, but the data display will also have to be adjusted. For example, if you use a transmission line (instead of lumped elements) to attain stability and optimize the length and/or width of the line, these parameters can be displayed on the data display by inserting new listing columns.