www.delorie.com/archives/browse.cgi   search  
Mail Archives: geda-user/2011/10/27/01:03:45

X-Authentication-Warning: delorie.com: mail set sender to geda-user-bounces using -f
X-Recipient: geda-user AT delorie DOT com
Message-ID: <4EA8E608.7020002@innocent.com>
Date: Thu, 27 Oct 2011 01:03:04 -0400
From: Gus Fantanas <fantanas AT innocent DOT com>
User-Agent: Mozilla/5.0 (X11; Linux i686; rv:7.0.1) Gecko/20110929 Thunderbird/7.0.1
MIME-Version: 1.0
To: geda-user AT delorie DOT com
CC: Gabriel Paubert <paubert AT iram DOT es>
Subject: Speaking of Microwaves (WAS: Re: [geda-user] Working with a 0.1mm
grid)
References: <CAKakQceJ8GBzX+jHqrhpD2D+-f1eoMqb7h5igJhHe-DuwQB1aQ AT mail DOT gmail DOT com> <20111021025514 DOT GF20384 AT malakian DOT lan> <1319310645 DOT 13417 DOT 8 DOT camel AT localhost> <201110230311 DOT p9N3BRr8005619 AT envy DOT delorie DOT com> <20111023185825 DOT GA24148 AT malakian DOT lan> <20111025120859 DOT GA5110 AT iram DOT es> <201110251224 DOT p9PCOk8L024200 AT envy DOT delorie DOT com> <CAKakQcegqKNU35Z1rSFPre-z9DhVut7GUMdr+iV9+k8fVRrkVQ AT mail DOT gmail DOT com> <20111026082721 DOT GA18280 AT iram DOT es> <1319670477 DOT 5698 DOT 8 DOT camel AT localhost> <20111026234856 DOT GB7333 AT iram DOT es>
In-Reply-To: <20111026234856.GB7333@iram.es>
Reply-To: geda-user AT delorie DOT com

On 10/26/2011 07:48 PM, Gabriel Paubert wrote:
> On Thu, Oct 27, 2011 at 12:07:57AM +0100, Peter Clifton wrote:
>> On Wed, 2011-10-26 at 10:27 +0200, Gabriel Paubert wrote:
>>
>>>> Personally, I've noticed a big improvement in snapping to the ends of
>>>> off grid lines (thanks Peter!), which is something I often need to do.
>> (Thanks!)
> And thank you very much for fixing the insert tool! Just pulled and
> compiled, it works fine.
>
>>> Indeed a few things are easier to do, so there is definitely progress
>>> in this area. But I've also noticed sometimes problems with microscopic
>>> examination of the result.
>> If you can reproduce it, and have a test-case with current git HEAD,
>> please send it along. It may be as simple as a computation which doesn't
>> take rounding into account properly.
> I shall try when I hit it again. I have also a polygon dicer (at least I believe
> it is) problem somewhere which I want to submit when I have more details.
>
>>> I'm designing right now with PCB some very high resolution circuit on alumina,
>>> where design rules can be down to 10µm/0.4mil minimal width and spacing,
>>> although I stay at a more reasonable 50µm/2mil for my first thin film circuit.
>> What is the application?
> Switching of microwave signals. Actually there are two different circuits,
> one based on RFMD's RFSW2041D and another one based on Hittite's HMC975.
> Both circuits have a square shape whose side is 8.89mm (350 mil).
>
> Actually the design of the (milled aluminum) enclosure is (at least for me)
> much more difficult than the PCB, in which everything is at an unusual
> scale, but otherwise very simple (the most complex of the 2 circuits
> has less than 10 components).
>
> 	Regards,
> 	Gabriel
>
>
Speaking of microwave design, I wonder, if one wants to do stripline 
design and has to use open-shunt stubs, can the ends of the traces be 
straight instead of oval?  If not, could one workaround be, perhaps, 
creating patch (one-pin footprint) to terminate an open shunt?  The 
width of such pseudo-component would be the same as the width of the 
trace it "terminates" and the total length of the two would be the 
calculated length of the shunt.

I am not sure how this trick would work for microstrip, though, as the 
terminating "pseudo-component" would be positioned between planes.  This 
case is probably very rare.

I use the version of PCB that came packaged with Ubuntu 11.10.


Regards,

Gus Fantanas


- Raw text -


  webmaster     delorie software   privacy  
  Copyright © 2019   by DJ Delorie     Updated Jul 2019