EEVblog Electronics Community Forum
Electronics => RF, Microwave, Ham Radio => Topic started by: i_am_mry on September 14, 2017, 08:55:35 am
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Hello all,
I'm creating microstrip 50-to-75 ohm wideband transformer. Here is my draft:
(http://www.radioscanner.ru/uploader/2017/50to75.png)
And my questions are:
Can i bend quarter-wave parts?
Is there any shortening factor for the each bend?
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What do you mean "bend"? As in, turning corners, in the PCB layout?
Use arc segments (trace length = mean arc length), 45 degree corners (close enough not to worry about), or 90 degree corners with a chamfer (trace length follows the inside path).
I doubt the quarter-wave lengths are very critical: your bandwidth is quite large (>50%). Can always design it for extra bandwidth (the result will be a couple extra steps), to get even looser tolerances.
Note that the trace edge-to-trace edge distance should be 2-3 trace widths minimum.
Tim
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Why not using a tapered transition instead of the stepped one? Doesn't the taper give more bandwidth naturally?
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What do you mean "bend"? As in, turning corners, in the PCB layout?
Hi Tim, Thanks for detailed answer.
Yes, just the turning corner, to make PCB more compact.
or 90 degree corners with a chamfer (trace length follows the inside path)
(http://www.radioscanner.ru/uploader/2017/mitred_corner.png)
As i understand, in this case "inside path" will be summary length of red edges. Is it correct?
Why not using a tapered transition instead of the stepped one? Doesn't the taper give more bandwidth naturally?
Thanks for a tip. I'll look on it.