Sorry, but it's true...
We use square zing lanes for two reasons... Delay and reduction of e-line propagation of near by fields.
Have it your way, but that is how I've understood and used them for years.
Now of they were circular in a square location, then that would constitute an inductor.
You can argue all you want about it. It won't change anything.
Jamie
No it's true that delay lines are ALSO made that way, but on the board I'm talking about it's a choke. It's conncted to the power supply. You do not connect to power through a delay line.
Le Sun, 19 May 2013 17:14:38 -0400, Tom Del Rosso a écrit:
Sure you can. Just make it lambda/4.
You can use a delay line to connect power? What are you delaying?
Doesn't
the
I've seen the sparkgaps - I imagine they may be a "one use only" feature. Are they?
Le Sun, 19 May 2013 23:24:00 -0400, Tom Del Rosso a écrit:
Transmission lines transform impedances they have on one side (ZL) to another impedance on the other side (Zin).
For a lossless line: Zin=Zc (ZL + Zc Tan(Lr))/(Zc + ZL Tan(Lr))
with Lr=2 pi len/lambda (Lr is the reduced length in radian and len the line length)
At lambda/4 a shorted line gives Zin= Zc Tan(Lr) with Lr->pi/2 and transforms the s/c into an open circuit.
Obviously, at DC it's no more lambda/4 and Zin=ZL=0.
This obviously doesn't hold for wideband signals.
...
^^ You see it all the time on microwave stuff. Wikipedia has a picture of a... 20-some GHz satellite board, stubs and filters and amps all over. Looks cool. They use thin 1/4 wave traces as bias tees all over (usually with some additional LC bypass and filtering action, too).
Tim
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