Learning Forum

[Swoopoo]

Hello,

I have imported my HFSS model into circuits and can replicate the S11 parameter there with no issues. After impedance matching with the smith tool and confirming the desired result in circuits I push the excitation to HFSS. After reanalyzing HFSS with the pushed excitation (Yes - under edit sources the excitation has changed) the S11 parameter didn't change and the model is not matched.

Does anyone know a solution to this problem?

[Praneeth]

Pushing the excitations from circuit to HFSS is sufficient for the cosimulation. This is called the dynamic link and it takes effect immediately.
You do not need to simulate again for this. This can be confirmed by looking at the excitations like you have mentioned.
For comparison of the results before and after cosimulation, it is advised to copy and paste the S parameters before performing cosimulation.
Please go through this video course - Cosimulation Using Ansys HFSS - ANSYS Innovation Courses for better understanding of the cosimulation concept and see if you can achieve the required matching.
All the very best.

[Swoopoo]

Hello unfortunately that is not the case. I followed multiple courses and guides on the dynamic link feature in ANSYS HFSS. But in contrast to their solution mine looks like this:
This is the circuit simulation. As one can see the unmatched red curve and the green curve after applying the matching network. The circuit simulation displays the desired result and confirms the matching should work.

Now the same plot before and after pushing excitations in HFSS:
The red (before) and green (after) curves overlap because the matching network excitation was NOT applied to HFSS even tho the software says the excitation push was successful. I'm really confused since the matching apparently worked, according to ANSYS Circuits.

The Model is a DrivenModal Solution (tried with Terminal Solution as well - same result) with one lumped port as excitation.

I'm at my wits end to be honest.

BR
Swoopoo

[Praneeth]

Please share the schematic of your circuit to help us serve you better.
Best regards.

[Swoopoo]

The Source is a Microwavegenerator with 28V at 2.87GHz. The Load is a wire loop with a lumped port as an excitation.
I need to match the 50 Ohm impedance from the source to the impedance of the load. There are two workflows I found - one stemming from the ANSYS video and one from the internet.
ANSYS workflow:
Impedance match from the smith chart center (50 Ohm) to the complex conjugate of the impedance of the source. This is the way I'd imagine it being correct, since this applies 50 Ohms at Port 1 and the to be matched impedance at Port 2 (Load side).

An alternative I found on the internet - which produces amazing results according to ANSYS (see first image in my post above) is to start at the impedance of the load and match it to 50 Ohm and than inverting the direction of current flow through the matching network.

Independent of what workflow I follow, I can't manage to get the desired effect in HFSS. The model behaves unchanged after pushing the excitations.

Do I need to use a special port for the matching network influence to take effect?

[Dan Dv]

Note that the dynamic link will not change the s-parameter results inside of HFSS. Pushed excitations only change the results that depend on those excitations, such as field plots. The combined s-parameters of the dynamic link between the Circuit tool and HFSS can only be seen through preforming an LNA in Circuit and plotting the s-parameters in Circuit.

[byron.montgomery]

I'm having the same issue, no matter what I do "Push Excitations..." only looks like it's replotting all the far fields. Even after putting some amplifiers in line I still can't get the far fields to reflect the new excitations.

[Joe O'Reilly]

Push Excitations is not working for me. HFSS 3d plots are not being updated even though status bar says the push was successful. Has this issue been resolved?

[Dan Dv]

Joe O'Reilly, which plots are not getting updated? Note that pushed excitations will not change the s-parameter plots in HFSS. Only field plots provided you plot based on the pwl excitations that got pushed from the Circuit tool. 

The only way to see the combined s-parameters is in the Circuit resutls. 

[Joe O'Reilly]

Dan. I am looking at far field plots at 6.5GHz in HFSS. The circuit file source is microwave set to 1V AC and 6.5GHz. Still not updating HFSS. Is there any way I could send you my file to see if I am doing something wrong?

[Dan Dv]

Hi Joe. Unfortuantely no, we cannot look at project files sent through this forum. If you are a full commerical customer, you can create a Service Request throught the customer portal. Or if you are with a Channel Partner, they should be able to provide direct support. 

A couple of things to check. If you right mouse click on the Excitations icon and choose edit soruces, make sure that the magnidue/phase properties are pwl based indicating they are getting info from the Circuit solve. 

 

I'd also try making some kind of radical change to the circuit just to double check if the fields are changing or not. 

[Joe O'Reilly]

Dan. I am making drastic changes to the match and still not seeing it pushed to the far fields. This is my HFSS source parameters.

[Dan Dv]

Hi Joe. That does look correct from here. Are you a direct or Partner based Ansys customer? 

 

[Joe O'Reilly]

Dan. Good question. How would I find that out?

[Dan Dv]

The first order question, do you have the full version of software, or the student version? If you are a corporate customer with the full version, does you company but directly from Ansys or through one of our Channel Partners? You may have to check in with your IT department to verify that. 

[Joe O'Reilly]

Full version. I am pretty sure we bought directly from Ansys.

[Dan Dv]

Hi Joe. Yes, in that case you should be able to open a Service Request on the Ansys Customer Portal.

If you have trouble logging in, there is more information about how to do that on this page:
https://webapps.ansys.com/era/ssosupport/customerportalhelp

Please put in a SR ticket and myself or one of my colleagues will be able to assist further. Once the ticket is in the system you will be able to share the project with us. 

[Joe O'Reilly]

Dan. Logged into the Customer Portal. Can't find service request. Can you point me there?

[Dan Dv]

Sure. Now that you are on the portal: To submit a Service Request , select Training
and Support > Submit &Check Service Request on the top menu, or the
bottom of the webpage.

[Joe O'Reilly]

Dan. My page does not have those options. I am signed in.

[Dan Dv]

Hi Joe. Hmm, that might imply that your support is handled by one of our Channel Partners. This forum does not give me enough info to access your account details. But if you send email to ansys-community-help@ansys.com and aks if you are a direct customer or a Channel Partner account they will be able to look you up and help you obtain support.