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It is possible to plot the output variables over the sweep, provided that the correct context is selected while defining the output variable. Kindly select the sweep (dicrete type) as the solution under the context.
Please go through "specifying output variables" section in the HFSS help pdf document for detailed information. Alternatively, you can access this information from the online version of the help document here - Ansys Electronics 2023 R1.
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