RE: gEDA-user: trace calculation[Scanned]

["Robert Thorpe" <Robert.Thorpe@xxxxxxxxxxxx>]

Microvias in particular are thin and have significant inductive
reactance at high frequencies.  Normal vias are not so bad. 

> -----Original Message-----
> From: owner-geda-user@xxxxxxxx 
> [mailto:owner-geda-user@xxxxxxxx] On Behalf Of DJ Delorie
> Sent: 05 January 2006 18:39
> To: geda-user@xxxxxxxx
> Subject: Re: gEDA-user: trace calculation[Scanned]
> 
> 
> > Why? Via doesn't have much more inductance than a piece of 
> trace, does 
> > it?
> 
> At high enough frequencies, traces are waveguides, not just 
> conductors.  Vias have nontrivial geometry relative to the signal.
> 
> That reminds me of another optimization I'd like to implement 
> in the future.  Instead of corners, treat all traces like 
> elastic bands, so that they end up as sweeping curves 
> (lines+arcs) with no corners at all (except for 3-trace 
> nodes).  I want this myself just because it makes the board 
> look pretty, but I wonder if gentle curves provide better 
> waveguide performance than corners?
> 
>