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How to calculate inductance of spiral inductor by using HFSS and ADS??

Hi, I am a newbie in RFIC design.

I want to design a spiral inductor on chip. Follow some instruction on internet:

First, I draw it in HFSS, simulate and extract the S-parameter to s2p file. After that, I use ADS to calculate the inductance:

Attachment 81351

I don't know why it's wrong. The inductance look like crazy

Attachment 81352

Can anyone help me? Thank in advance.

Re: How to calculate inductance of spiral inductor by using HFSS and ADS??

Quote:

Originally Posted by

**hien.rfic** I don't know why it's wrong. Can anyone help me?

Yes, but why do you open an new thread instead of following instructions in your previous thread?

I do this RFIC inductor workflow support for paying customers every day. Here you can get my help for free, but you seem to ignore questions and troubleshooting instructions.

Re: How to calculate inductance of spiral inductor by using HFSS and ADS??

Quote:

Originally Posted by

**volker_muehlhaus** Yes, but why do you open an new thread instead of following instructions in your previous thread?

I do this RFIC inductor workflow support for paying customers every day. Here you can get my help for free, but you seem to ignore questions and troubleshooting instructions.

I'm sorry. Because I'm in a hurry. I read your suggestion but I don't know what I should do. I worried that I cannot ask you too much and you don't have time to answer my foolish questions. I'm ever so sorry. I greatly appreciate your kindness.

Re: How to calculate inductance of spiral inductor by using HFSS and ADS??

Quote:

Originally Posted by

**hien.rfic** I read your suggestion but I don't know what I should do.

Replace your S2P block with an ideal 10nH inductor component, and test if your equation now works.

The purpose of this test is to see if the problem is in the equation, or in the s2p file. I sometimes have inductor s2p files where the extracted inductance looks wrong (negative) because there is some open circuit (gap) in the model. With an ideal L, you can test the equation and see if your problem is in the equation or in the S2P data.

1 Attachment(s)

Re: How to calculate inductance of spiral inductor by using HFSS and ADS??

Quote:

Originally Posted by

**volker_muehlhaus** Replace your S2P block with an ideal 10nH inductor component, and test if your equation now works.

The purpose of this test is to see if the problem is in the equation, or in the s2p file. I sometimes have inductor s2p files where the extracted inductance looks wrong (negative) because there is some open circuit (gap) in the model. With an ideal L, you can test the equation and see if your problem is in the equation or in the S2P data.

I test with ideal inductor and the result from equations are right. The problem is in the s2p file. I also check the HFSS structure. I change some variable and now I have a good inductor. Thank you very much. I really appreciate your advice.

Attachment 81406