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Electronics => RF, Microwave, Ham Radio => Topic started by: jujun on April 24, 2019, 12:56:44 am

Title: Mechanical 3D filter realization from coupling matrix
Post by: jujun on April 24, 2019, 12:56:44 am
Hello,
I feel the need to know more about microwave filter that are made of coaxial
cavity cell that are coupled, and sometime with a topolgies like "cascaded tuplet" or "cul de sac".

It seems that this kid of filter that is everywhere (like in mobile phone base station) is first made with a software that generate a coupling matrix. (ex : http://www.gwtsoft.com/ (http://www.gwtsoft.com/) ) And then this coupling matrix is used to make the mechanical filter.
But everything I read about it is kind of magical, because there is nothing about how it is done.

For exemple here : https://www.cst.com/solutions/article/filter-design-technology-2017 (https://www.cst.com/solutions/article/filter-design-technology-2017)
There is nothing about the mechanical part, it's "magical".

So I guess that you have to model one 3D cell and then build your filter by cascading them ? But how to use the coupling matrix to automate it ? It must be a quick way to do it.

Any pointers on how to do it ?
Any pdf about it ? or book ?
Is there any software that will do the work ?

Thank you


Title: Re: Mechanical 3D filter realization from coupling matrix
Post by: rfeecs on April 24, 2019, 09:42:31 am
Here's one pdf from the website you referenced.  The whole process is gone through, including determining mechanical dimensions:

http://www.gwtsoft.com/Misc/Hagensen3.pdf (http://www.gwtsoft.com/Misc/Hagensen3.pdf)