Vinod, I concur with Steve's comment, a 2D solver will probably be sufficient. Some other options: AppCAD is a free little application from Agilent that should get you in the ballpark with your CPW calculations. Also if you have access to ADS, the Linecalc tool would also do. Ansoft Designer also has a transmission line calculator that would do this. I would assume most other simulation tools have some similar capability. My experience with empirical solutions for CPW characteristics was based on formulations in Wadell's Transmission Line Design Handbook. As an academic exercise, I implemented some approximations for the elliptic integrals in Excel, which was very cumbersome. The results were in general agreement with the tools I mention above, so this text may be an alternate source of closed form expressions for you. On a side note, one thing to be aware of (it may seem obvious, but has bit me once). Some methods/tools will ask for Er and calculate Eeff, whereas others will assume you enter Eeff. If you have a decent gap width, and a high Er substrate then the difference will be significant (up to about 2x in my experience). -Brett -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of steve weir Sent: Wednesday, August 25, 2004 3:21 PM To: koul@xxxxxxxxxxxxxxxxx; si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: CPW Any decent 2D solver will give you a reliable answer. Steve At 03:57 AM 8/26/2004 +0530, Vinod Koul wrote: >Hello SI experts, > Can any body help me in the synthesis of CPW. > I tried to calculate the CPW parametrs using the formulation given >in RAINEE SIMONS: coplanar waveguide circuits, components and systems, >wiley interscience. this is the only place which deals with synthesis >of CPW. but has errors, i checked with the orignal ref and made >corrections. well getting to point, there two sets of formulae are >given 1st calclates slot width given all other things, and second >central conductor width. >But both these sets are not consistent with each other, like i tried >to simulate both equations in MATLAB, and answers in both were not >consistent with each other. For eg i calc, S=3D 272Micrometer for = er=3D13, >Z=3D50, w=3D100u, h=3D100u, now for second set, its giving w =3D 18u, = for the >same data as abive (s=3D 272u)!!!! >can anyone help me out >______________________________________________________ >Vinod Koul >Graduate Student. >Microwave Lab. >Dept of ECE. >IISc, Banglaore. > >Cell No +91 9886034503 >Lab +91 80 2293 2853 >________________________________________________________ > >------------------------------------------------------------------ >To unsubscribe from si-list: >si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field > >or to administer your membership from a web page, go to: >//www.freelists.org/webpage/si-list > >For help: >si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > >List FAQ wiki page is located at: > http://si-list.org/wiki/wiki.pl?Si-List_FAQ > >List technical documents are available at: > http://www.si-list.org > >List archives are viewable at: > //www.freelists.org/archives/si-list >or at our remote archives: > http://groups.yahoo.com/group/si-list/messages >Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: =20 //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu =20 ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu