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Modeling >> Transmission Lines and Other Distributed Devices >> linecalc parameters for 4 layer 0.062'' PCB parameters?
https://designers-guide.org/forum/YaBB.pl?num=1282526172

Message started by liletian on Aug 22^nd, 2010, 6:16pm

Title: linecalc parameters for 4 layer 0.062'' PCB parameters?
Post by liletian on Aug 22^nd, 2010, 6:16pm

Hi Guys
I am using PCB to make a transmission line. I want to make a 50 Ohms transmission line. I used 4 layer 0.062 inch PCB, 1 oz copper.
Here is the parameter I use, please comment:
Er 4.7
Mur 1
H 0.29 mm
Hu ? I am not sure, I am using 1.6 mm
T 0.035 mm
Cond 5.96e7
TanD 0.02
Rough 0
Dielectrical LossModel 1.o , not sure, use default value
FreqForEpsrtanD 1e9, not sure, use default value, please comment
LowFreqForTand 1e3 , not sure, same as above
HighFreqForTanD 1e12 not sure, same as above
Please comment on those parameters for PCB FR4 4 layer 0.062 inch, 1 oz copper in ADS linecalc.
Thanks

Title: Re: linecalc parameters for 4 layer 0.062'' PCB parameters?
Post by rfcooltools.com on Aug 24^th, 2010, 9:25am

liletian,

for er=4.7 use a height to width ratio of 5:7 (5 height is the distance from the bottom of the conductor to the ground plane). As long as both dimensions are the same units the ratio stands. I have neglected the loss tangent in my calculations since it is small and may be negligible for short trace lengths.
visit
http://rfcooltools.com and place a t-line and try out different combinations to suit your needs

Title: Re: linecalc parameters for 4 layer 0.062'' PCB parameters?
Post by vp1953 on Aug 24^th, 2010, 5:43pm

Hi Rfcooltools,

Everyday i learn something more on the capabilities of your software!! A standalone version would be good to have.

Title: Re: linecalc parameters for 4 layer 0.062'' PCB parameters?
Post by rfcooltools.com on Aug 25^th, 2010, 8:41am

Thanks vp1953 for the interest and for checking it out.

There are two reasons I am reluctant to change this. First with the Java webstart feature any bugs that get reported can be changed so that the next time you use it gets the latest version, since I don't have professional software testers I occasionally find bugs that require an update from time to time. This ensures that the software is always the latest. Secondly I am presently pre-occupied trying to write an EM simulator which so far exceed the default memory allowance that Java can support, I can request more memory at startup which might be declined depending on the operating system, or I might have to break solving into smaller chunks and thus slow down the experience. When I have a working version of it I plan on rethinking how the whole program is packaged. For the time being webstart Java version does require a web connection to initiate the software.

I may be able to accommodate part of your needs in the interim.

Do you want a stand alone version because you are not connected to the web all the time and want to run it? (this might be a simple change)
Is the End User License Agreement questionnaire a nuisance? (I might be able to place a cookie that will show this once )
Does the security questionnaire that your operating system asks during install make you nervous? (Better documentation on the website might relieve some of these concerns)
Sorry I took up others time with this off topic discussion.

thanks
http://rfcooltools.com

Title: Re: linecalc parameters for 4 layer 0.062'' PCB parameters?
Post by vp1953 on Aug 25^th, 2010, 5:10pm

Hi Rcooltools,

- yes part of the reason is that i am not connected to the web all the time but this is not a big deal if making a standalone version is difficult to implement
- the end user agreement could be had just for the first time (or maybe periodically if needed) instead of every time
- the security credentials is not a big deal for me since i know your good credentials from this forum; HOWEVER, for someone who did not know you, it would make them nervous.

One other possible feature to add at your convenience would be to limit component values to less than a certain value for the filter synthesis. For example, the filter design uses with inductors of values of several 100 nH (which may be too large) and it is possible to put an upper limit on this, that would be useful.