Learn how to configure a Simulink® model to make S-parameter measurements on a given circuit design. The chosen device under test is a T-coil circuit, constructed using Simscape™ components. The circuit is exercised using the simulation engine in Simulink in the time domain while measurements are made in the frequency domain. The two port S-parameter measurements are derived from a cross-spectrum–based transfer function estimation technique. Learn about the benefits of using a directional bridge circuit as compared to not having such an S-parameter measurement technique at your disposal.

Without a directional bridge or directional coupler, the reflected coefficients would be much harder—if not impossible—to obtain. At the same time, learn about the drawbacks associated with such an empirical S-parameter measurement method. The technique shown doesn’t scale well for a large numbers of ports. It can also be tedious to configure, and simulation times can be lengthy and/or suffer from aliasing issues. All of these issues are demonstrated using Simulink and Simscape Electrical™ as the simulation platform.

Learn more about Simscape Electrical: bit.ly/2RWENG7

Access the R2024b Simulink model used in this video on GitHub®:
github.com/kschutz68/measure_sparam_dbridge.git
vgithub.com/kschutz68/directional_bridge_intro.git
github.com/kschutz68/wheatstone.git

Chapters:
00:00 Introduction
00:25 Different Ways to Determine S-parameters Given a Particular Circuit
02:55 Bridgeless Approach to Measuring S-Parameters
07:15 Directional Bridge–Based S-Parameter Measurements
10:30 Limitations of the Empirical Approach
16:15 Start with the Right Answer
16:55 Run Bridgeless S-Parameter Model in Simulink
19:00 Run Directional Bridge Testbench Model
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