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gocoba

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Ideal transmission line in Cadence
Jan 26^th, 2010, 6:57pm

Hi there,

I have a question, is there an ideal transmission line model in Cadence like TLine in ADS? ADS has ideal Tline models and I use them to get the electrical length values I need. Then I use some EM software like Sonnet, etc to model my lines to get as close a match as possible to the ideal line electrical length and characteristic impedance values.

So, just wanted to know if there is ideal one in Cadence.

Thanks!!
Albert

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pancho_hideboo Senior Fellow Offline Posts: 1424 Real Homeless	Re: Ideal transmission line in Cadence Reply #1 - Jan 26^th, 2010, 7:20pm Use "analogLib/tline". See http://www.designers-guide.org/Forum/YaBB.pl?num=1231344965/1#1
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gocoba

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Re: Ideal transmission line in Cadence
Reply #2 - Jan 27^th, 2010, 5:13pm

Hey thanks!!

But I have a question of setting up these parameters in Tline.
Suppose I have a line with 30 degree at 60GHz, suppose there is no delay time (ideal line only), what should I set for physical length?

30/360 * lamda = 1/12* 3e8/60e9 = 420um? I dont have to consider dielectric constant since this is a perfect line, is that correct? Also, what is the normalized length? the default is 0.25, does that mean it is set to be a quarter wave TL?

Thanks a lot in advance!

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pancho_hideboo

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Re: Ideal transmission line in Cadence
Reply #3 - Jan 28^th, 2010, 3:25am

gocoba wrote on Jan 27^th, 2010, 5:13pm:

Suppose I have a line with 30 degree at 60GHz,
suppose there is no delay time (ideal line only)

What do you mean by no delay time (ideal line only) ?

gocoba wrote on Jan 27^th, 2010, 5:13pm:

what should I set for physical length?
30/360 * lamda = 1/12* 3e8/60e9 = 420um?

Right.

beta=2*pi/lamda, theta_rad=30/180*pi,
Length=theta_rad/beta=30/180*pi*lamda/(2*pi)=30/360*lamda

gocoba wrote on Jan 27^th, 2010, 5:13pm:

I dont have to consider dielectric constant since this is a perfect line,
is that correct?

Correct.
However "dielectric constant" is considered as wavelength or wave velocity equivalently.

gocoba wrote on Jan 27^th, 2010, 5:13pm:

Also, what is the normalized length? the default is 0.25,
does that mean it is set to be a quarter wave TL?

Yes.

Read message of "spectre -h tline" surely, before posting questions.

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« Last Edit: Jan 28^th, 2010, 8:37am by pancho_hideboo »

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http://www.youtube.com/watch?v=mjIxGh55bMM&feature=related

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