Learning Forum

[Furkan Yuşa Kılınç]

Hello, I hope you are all well. I wanted to design a 30 dB 2.4 GHz stripline coupler in HFSS and have followed this tutorial from ANSYS:

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Because I wanted to do a 2.4 GHz version, I have used the TRL in ANSYS circuit to calculate the exact width, gap size and length and put them in the HFSS design. These are my screenshots for the design and setups:

Now, when I try to put this design into ANSYS circuit and see if it works as a reflectometer, I have created this circuit:

I have checked the ports and they are right. Then, I have sweeped the frequency to see the frequency response of the reflection coefficient which is added as an output variable as "max(V(reflected))/max(V(transmitted))". This is the result of it:

It is a bit confusing graph but it can be seen that the coupler is not working so well even in 100 MHz difference. To compare the results with the stripline coupler from the ANSYS Circuit TRL, I have created the same circuit using the stripline element from there and the results were so close to correct value even in the 5GHz range. What do you suggest? What could be the reason for this? Can I get a good directional coupler close to the TRL one or my coupler is what it can possibly best become? Thank you in advance.

[Furkan Yuşa Kılınç]

Is there anyone to help me?

[Praneeth]

Hi,

Thank you for reaching out to the Ansys learning forum. Your patience is much appreciated.

It is understood that you are not able to replicate the response of your HFSS design in Circuit. Please check the response of your coupler in the circuit for linear network analysis to see if you are getting the same response in both HFSS and Circuit. If you are new to Ansys Circuit, then please go through this video for the step by step approach - Cosimulation Using Ansys HFSS and Circuit - Lesson 2 - ANSYS Innovation Courses. 

Hope this helps.

Best reagrds,
Praneeth.

[Furkan Yuşa Kılınç]

Hello, I have double checked from the video that you have provided and also, I have compared the linear analysises, the linear analysis of the coupler in Circuit and in HFSS are the same.