examples of smith chart two series stubs pdf

The Smith chart is a special polar plot format often used for the design of matching networks and for stability analysis. The elements of the S-parameter matrix are complex and can be visualized on a Cartesian plot in terms of magnitude and phase or on a polar plot. Visualization is the first step for inspecting S-parameter data. Goal is to get to origin of Smith Chart where r 1, g 1, and 0 Method: 1 Normalize load and plot (A). Usually the stubs are separated by standard distances: /4, /8, or 3/8. S-parameter data can also be analytically calculated for a given component prior to its realization via behavioral models, circuit analysis, and electromagnetic simulation, as offered, for example, by Antenna Toolbox™ and RF PCB Toolbox™. The double stub method fixes the location of the stubs and varies the lengths.

Automated workflows enable scale-up testing, validating scenarios, extracting statistical information on device performance, and easily sharing results with customers and colleagues. RF Toolbox and Instrument Control Toolbox™ allow you to combine S-parameter measurements and data analysis. Typical tasks include de-embedding, cascading, and visualizing S-parameters. As a result, RF test engineers must often process a large amount of S-parameter data. S-parameters are measured using vector network analyzers (VNAs) over different operating conditions. Measuring and Visualizing S-Parameters with MATLAB Most RF analysis tools and simulators can read and write Touchstone files, thus making them a portable file format to exchange measurements and design information. Portable: S-parameters are often stored in a standard file format called Touchstone ®.

Benefits of Using S-ParametersĮasier to measure than Y or Z matrices: The measurement of Y or Z parameters requires open- and short-circuit terminations that are challenging to maintain at RF and microwave frequencies, therefore their measurement is less reliable than S-parameters.įlexible: For circuit analysis or simulation, S-parameters can be easily converted to Z-parameters, Y-parameters, and other linear matrices. The value of S 11 provides a direct measure of the port matching condition, that is, S 11= 1 represents an open circuit S 11= -1 represents a short circuit and S 11= 0 represents a perfectly matched circuit. In this example, S 11 is defined as the ratio of the reflected wave to the incident wave at port-1 while port-2 is terminated on the characteristic impedance.

Examples of smith chart two series stubs pdf