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Regarding Microstrip impedance tutorial in 3.5a

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Hello all,

a note and a question regarding the tutorial calculating the impedance of the microstrip.

First off, in the model documentation I think there is a slight error found on page 25 of the RF model library PDF. For the values of variables not solved for and linearization, it was told to choose the SAME effective mode index plotted (1.59) to place in the 'current solution' . Yet the documentation chose the Other effective mode ( 0.88 ) . It is a bit misleading unless I'm wrong somewhere at which point I hope you can correct me.

Second and most importantly, I have been trying to sweep the frequency and find the impedance of this microstrip for a range of frequencies other than the standard 1GHz. But for some reason, I was not able to sweep nu_rfw which is the 3D EM application frequency.
And when I tried to re-do the whole model from scratch with a different frequency, say 5 GHz, the GMRES solver would not converge!! Which is pretty odd if you ask me.

I doubt that I have done anything wrong because I repeated the exact same steps only with a different frequency than 1 GHz. So what is the whole issue with changing the frequency ?

Hope to hear from you soon,
regards,
MD

1 Reply Last Post May 10, 2010, 3:27 p.m. EDT

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Posted: 1 decade ago May 10, 2010, 3:27 p.m. EDT
Basically, all i want to know is Why does the impedance change significantly (or Cannot be calculated) when the frequency is taken from the beginning to be different than 1GHz.
If it sounds weird to you, that's because it is!

anyone? :)
Basically, all i want to know is Why does the impedance change significantly (or Cannot be calculated) when the frequency is taken from the beginning to be different than 1GHz. If it sounds weird to you, that's because it is! anyone? :)

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