Mini-Circuits ISC-2425-25+ Quick Start Manual page 10

Though this information is very useful, it alone is not sufficient to properly optimize the process. To find out the
frequency at which to heat (i.e., the match), a frequency sweep should be performed to assess the S11 parameter
across a pre-defined frequency band. This is done by briefly using low RF power and determining the S11 parameter at
various frequencies over a given frequency range. The resulting data can be formatted into a graph that provides insight
into the possible match within the tested frequency range. See figure 1 below.
In the example graph below, a 'minimum' S11 point can be seen around the 2450MHz range, this is the frequency where
the reflection is closest to 0 and the RF energy delivery into the load/process would be the most efficient.
Figure 1: S11 (dB) vs frequency & Reflection (%) vs Frequency
AN-50-001 Rev.: OR DCO-000695 (11/01/21) File: AN-50-001.docx
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