Band pass Coupled Line Filter Design -- Need Help

[steadymind]

coupled line filter

Hi,

I am trying to get design a coupled line bandpass filter at 11.5 Ghz in ADS. I Used linecalc and equations in pozar to get the width and length of the coupled sections MCFIL but it works at 10.8GHz instead.

When i use MCLIN instead of MCFIL i get it to work near 11.6Ghz . what is the difference between MCLIN and MCFIL.

how do i make it work at 11.5 GHz using MFLIN and what is the diffrence between MFLIN and MCLIN

 

[Abhishekabs]

coupled line filter design

I recommend you to use DG-Component to design filter.
It is a template, you just need to provide the specification & design is almost ready.
Check components palet for DG-components.
Best of luck
Abhishekabs

 

[steadymind]

line filter design

I cant use the DG template as I am supposed to design this for a project...

Do u any idea why this is resonating at a different frequency ?

 

[toonafishy]

bandpass filter design using coupled lines

MCLIN is a 4 terminal model. MCFIL is a two terminal model. Did you attach a MLEF to each of the unused terminals on the MCLIN?

 

[steadymind]

bandpass coupled line

Yes. It is working fine with MCLIN but now working with MCFIL.

Is there any correction factor that needs to be done. Isnt MCFIL basically MCLIN with ports 2,3 terminated with MLEF.

 

[lguancho]

coupled line bandpass filter ads

It is not so important to get accurate circuit simulation. What is important is the result of EM simulation, such as Momentum or Sonnet which takes into account of the housing effect. Remember that the edge coupled design is radiative (open end), you need to house it in narrow housing channel with an effective waveguide cutoff frequency higher than the desired stopband frequency of your filter.

In other word, you need to do initial design with any circuit simulator and later optimise the design using EM. The optimisation process should correct for any frequency shift in circuit simulation.

I only trust the EM result.

 

[Abhishekabs]

ads coupled line

I agree with lguancho, Try simulating your circuit in ADS momentum.
And tell us the results.
Then we can conclude something.

 

[steadymind]

coupled line bandpass filter designing on ads

Thanks lguancho and Abhisekabs the MCFIN worked fine in Momentum simulations but MCLIN I had to provide proper termination at the open ports to get a good response.