Hi everyone,
I am so new in designing filter, but now I need to design a micostrip filter using square open loop resonator. I read some papers about it, but i haven't got any ideas. Can anyone tell me what is the designing equation about it and how to design it?? Thanks.

 

I got a lot of hits with this query:
http://www.google.com/search?hl=en&q=microstrip+filter+design

but this page in particular had some interesting Excel tools that you could download:
http://tools.rfdude.com/Filter/filter.html

Fiddling with filters in the GHz region can be rather frustrating, particularly if you neglect to figure in things like parasitics, the dielectric characteristics of your selected board, enclosure dimensions, etc. - and the higher in frequency you go, the more critical things like that become.

 

Thank you for your help.
I had also search it in google, but the filter I designed needs to be specificed in using open loop resonator. I haven't any ideas about it. And I want to find out the designing equation of it. Pls help. Thanks

 

Try AppCAD 3.02 a free download from Agilent
http://www.hp.woodshot.com/

 

Well, you could always track down a demo copy of (formerly Eagleware) Genesys on Agilent's site:
http://eesof.tm.agilent.com/products/genesys/index.html

Eagleware used to be an independent company, and Agilent bought them out in 2005.
You can get a basic Genesys software package for around $4,000.

Or, you could take a look at the page I suggested.

 

Thank you for help.
I think the software is very powerful, but it is very expensive.
I want to design the square open loop resonator in microwave filter by hand cacultion.
However, how can I find out the equation of the filter?
I still haven't any ideas about it. Pls help. Thanks.