S‑Parameters Demystified for Cadence Simulations

[00:00:00]S-parameters, or scattering parameters, quantify how RF signals are reflected and transmitted in a multi-port network.

[00:00:08]Instead of voltages and currents, they describe the relationship between incident waves, labeled A, and reflected waves, labeled B, where A1 and B1 are present at the input and A2 and B2 at the output. Here, S11 represents the input reflection coefficient, indicating how much signal is reflected back at port one. S21 is the forward transmission coefficient, defining how much signal transfers from the input to the output. S12 captures reverse transmission, and S22 represents output reflection. These parameters enable the accurate characterization of matching, gain, isolation, and overall network behavior across frequency. Let us look at how you can simulate high-quality S-parameters using the Cadence Spectre simulator. Start by extracting Touchstone or MDIF data using an EM solver. Then, validate it with the S-parameter checking and fitting tool.

[00:01:04]Next, generate rational fit model using the fitting tool. Configure the end port to run a Spectre S-parameter simulation.

[00:01:12]Finally, you plot the results using the waveform viewer in Virtuoso ADE. This structured flow, recommended by Cadence, ensures accurate, reliable RF simulations compatible with Spectre. For additional details, please refer to the description.