Just a quick thought on this:
Unless all of your traces are horizontal and vertical, I would recommend
that you only use fills to square off trace ends. Placing rectangular pads
on non orthogonal traces will not leave the desired square end. For
example, a square aperture placed at the end of a 45 degree trace would
result in a trace that comes to a point. Certainly, you could utilize a
diamond shaped pad for this case. However, it would be difficult to extend
this philosophy to the more general case where a trace is placed at any
arbitrary angle. Using fills can prevent these kinds of problems. However,
it is probably also important to consider the size of the trace that is
utilized to generate the "filled" trace. Larger traces will leave a
"rounded rectangle" effect at the trace ends. Using smaller traces will
give the square corners, but can result in very large data files.
Best regards,
Max P. Henzi, CEO
Lavenir Technology
2440 Estand Way
Pleasant Hill, CA 94523
voice: (925) 680-7400 fax: (925) 686-5131
email: [EMAIL PROTECTED]
Web: www.lavenir.com
-----Original Message-----
From: Brian Guralnick [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, June 13, 2001 2:30 PM
To: Protel EDA Forum
Subject: Re: [PEDA] Microwave PCB layout
You can also put fills just at the end of your traces to square off the
corners.
_____________
Brian Guralnick
----- Original Message -----
From: "Henrik Thurfjell" <[EMAIL PROTECTED]>
To: "Protel EDA Forum" <[EMAIL PROTECTED]>
Sent: Wednesday, June 13, 2001 5:20 PM
Subject: Re: [PEDA] Microwave PCB layout
| John
|
| Thanks for your input.
| This is a 10GHz circuit and the RF guys have been pretty particular about
| the bevels. Now it would be interesting to know if beveling is just
another
| superstition. If rounded corners will work just as well or better, not
| introducing impedance transitions in the line, that would indeed make this
| task easier. Could your field solver answer that question?
|
| Henrik
|
| ----- Original Message -----
| From: John Haddy <[EMAIL PROTECTED]>
| To: Protel EDA Forum <[EMAIL PROTECTED]>
| Sent: Wednesday, June 13, 2001 8:42 AM
| Subject: Re: [PEDA] Microwave PCB layout
|
|
| > Protel doesn't handle RF layout well. It can't deal with stripline
| > design (e.g. defining a piece of stripline in schematic of specific
| > length and width doesn't map well to PCB - short of defining a
| > library full of segments (which doesn't provide flexibility in layout))
| >
| > With regard to beveled corners, I was shown a reference not long ago
that
| > discussed the origin of beveling. It turns out that beveled corners were
| > developed as a workaround because arcs couldn't be defined in the CAD
| > systems available at the time! Radiussed corners are supposedly better
| > than the approximation given by a beveled corner.
| >
| > I haven't personally used a field solver to confirm this, but some of
| > our RF designers were more than happy to allow the use of arcs in
| > preference to bevels (which are a right royal pain to do in Protel!).
| >
| > Cheers,
| >
| > JohnH
| >
| > > -----Original Message-----
| > > From: Henrik Thurfjell [mailto:[EMAIL PROTECTED]]
| > > Sent: Thursday, 14 June 2001 1:02 AM
| > > To: Protel EDA Forum
| > > Subject: [PEDA] Microwave PCB layout
| > >
| > >
| > > Hi all Protel fans
| > >
| > > How well can Protel handle microwave PCB layouts. You know, as
| > > beveled corners of strip lines.
| > > The default rounded trace end is a major obstacle in this case.
| > > Can that be changed to a square end?
| > > Can the mitering of corners be changed to "beveling"?
| > >
| > > Regards
| > > Henrik
| > >
| > > ============
| > > Henrik Thurfjell
| > > Megatron Engineering
| > > 1149 Susan Way, Sunnyvale CA 94087
| > > Direct 408 737 1718
| > > FAX & Messages 408 739 2429
| > > email: [EMAIL PROTECTED] or [EMAIL PROTECTED]
| > >
| > >
| > >
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