How to calculate width and space for parallel-coupled filter

[kpcheah]

calculate width of material

I am trying to design microstrip bandpass filter. I have calculate the even-mode and odd-mode characteristic impedance, but i dont know how to calculate the width and the space for the filter. Can anyone help me. Below is the data i obtain:

j (Z0e) (Z0o)
0 82.9367 37.6092
1 61.1600 42.3705
2 58.1839 43.8661

The thickness is 0.635 mm
relative dielectric constant is 10.2

Is there any e-book or any web-page have the information about this?
THX

 

[james cook]

you can calculate the width and space with HFSS. use the driven modal. 2 mode for a wave port.

 

[biff44]

Re: How to calculate width and space for parallel-coupled fi

I had the same problem recently. I had some filters to design, had an old excel file that gave the correct Zoe and Zoo's, but when I got them I did not know what to do with them! None of my software takes even/odd mode impedances anymore!

There used to be a program called TLine that did this calculaton (impedance to physical dimensions). You might look around for some shareware. This site looks promising, for instance:
http://atlc.sourceforge.net/tutorial.html

 

[RealAEL]

Re: How to calculate width and space for parallel-coupled fi

If you have access to ADS then LineCalc can do all you need. You will need perhaps to be a bit more specific about the material properties than just H and Er. These number therefore only approximate.

j___(Z0e)____(Z0o)____W_______S____
0 - 82.9367 - 37.6092 - 0.35 mm - 0.16 mm
1 - 61.1600 - 42.3705 - 0.54 mm - 0.52 mm
2 - 58.1839 - 43.8661 - 0.56 mm - 0.69 mm

 

[Azulykit]

Re: How to calculate width and space for parallel-coupled fi

You might find LINC2 software useful. I believe it is on the order of $500 or so.

 

[thaithien]

How can we set the freq for this calculation.I found that it doesn't affect much !

 

[tony_lth]

You can use AWR to simulate it. The freq is determined by length, the length should be lamda/4, a little shorter than it.