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S11-parameter from a 1-Port Microwave Heating Cavity

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Dear all,

I am trying to model the microwave heating cavity that I am working with (see the attached file for the general view of the system).
It's a rectangular waveguide (86x43mm) and only it has one port, and there is a coaxial cable between the generator and the cavity and this coaxial cable is connected to the cavity through coax to waveguide adapter.
What I want to obtain is S11-parameters when the cavity is empty and loaded (see the attached file for the port settings).
I obtained S11 results (see the attached file) without doing any special thing or arrangement in the simulation, in general it looks ok that we have a resonance at 2.46GHz but the thing is that the value is so low ca. -0.12dB. I have also a Network Analyser to check and correlate the simulation but the S11data is around -30dB (@2.45GHz).
I do not know what is wrong with the simulation, is there any special settings for obtaining the S11 parameters?
I would appreciate it if you could help me about this situation.

Thanks.


3 Replies Last Post 13.08.2016, 09:24 GMT-4

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Posted: 8 years ago 12.08.2016, 13:27 GMT-4
Do I need to introduce another port into the system, even if I do not have physical 2nd port?
Do I need to introduce another port into the system, even if I do not have physical 2nd port?

Edgar J. Kaiser Certified Consultant

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Posted: 8 years ago 13.08.2016, 05:24 GMT-4
Hakan,

without seeing the model my best guess is that the model simply misses the resonance due to its coarse frequency resolution. The resolution is only 10 MHz while the measured resonance is less than 1 MHz wide.

Cheers
Edgar

--
Edgar J. Kaiser
emPhys Physical Technology
www.emphys.com
Hakan, without seeing the model my best guess is that the model simply misses the resonance due to its coarse frequency resolution. The resolution is only 10 MHz while the measured resonance is less than 1 MHz wide. Cheers Edgar -- Edgar J. Kaiser emPhys Physical Technology http://www.emphys.com

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Posted: 8 years ago 13.08.2016, 09:24 GMT-4
Dear Edgar,
Thanks for the answer.
The solid state microwave generator work between 2.43 and 2.47 GHz. That's is why I always use this fq range and the lowest cut off fq of the cavity is 1.75GHz.
I also tried very tiny steps like 1MHz but the S11data did not change at all, the same peak at the 2.46GHz.
I just don't what I am missing for this simulation.
Dear Edgar, Thanks for the answer. The solid state microwave generator work between 2.43 and 2.47 GHz. That's is why I always use this fq range and the lowest cut off fq of the cavity is 1.75GHz. I also tried very tiny steps like 1MHz but the S11data did not change at all, the same peak at the 2.46GHz. I just don't what I am missing for this simulation.

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