Step 4 - Find The Best Frequency For Rf Energy Delivery - Mini-Circuits ISC-2425-25+ Quick Start Manual

2.5 Step 4 – Find the best frequency for RF energy delivery
Now you have the GUI installed you will want to run your first application. During an RF heating process, the user wants
to make sure that the available RF energy is used optimally to heat up the load (the chosen material). In a typical
application, this is not a trivial thing to do: The frequency where energy is effectively transferred into the load is called
the "match" and needs to be determined. A good match means most of the RF energy is absorbed by the load,
whereas a bad match means a large portion of the energy is reflected back into the RF generator system.
A match can be expressed in different ways depending on the units used to measure RF power. When
measuring the power using dBm, the match is expressed as 'S11':
Here, S11 is expressed in dB, and the powers PFWD and PRFL are expressed in dBm.
A lower value of S11, the better. For example, a value of about -13dB would indicate that more than 95% of the forward
RF power is used in the cavity.
When measuring the power using watts the match is expressed as "Reflection":
The reflection has a value typically between 0 and 1, and is expressed as a percentage (%); The powers PFWD and
PRFL are expressed in watt. The closer the reflection is to 0%, the better.
The GUI displays forward power, reflected power and reflection (%) or S11 (dB) in the lower left corner. Switching
units (watt <-> dBm) is done by clicking the 'unit' button of any of the three displayed parameters:
AN-50-001 Rev.: OR DCO-000695
This document and its contents are the property of Mini-Circuits.
S11 =(P
Reflection= (P
(11/01/21) File: AN-50-001.docx
- P )
RFL FWD
/ P )
RFL FWD
Page 7 OF 19