Author Topic: Microstrip bending in a transformer  (Read 1090 times)

0 Members and 1 Guest are viewing this topic.

Offline i_am_mry

  • Newbie
  • Posts: 2
  • Country: ru
Microstrip bending in a transformer
« on: September 14, 2017, 08:55:35 am »
Hello all,

I'm creating microstrip  50-to-75 ohm wideband transformer. Here is my draft:



And my questions are:
Can i bend quarter-wave parts?
Is there any shortening factor for the each bend?
 

Offline T3sl4co1l

  • Super Contributor
  • ***
  • Posts: 13546
  • Country: us
  • Expert, Analog Electronics, PCB Layout, EMC
    • Seven Transistor Labs
Re: Microstrip bending in a transformer
« Reply #1 on: September 14, 2017, 11:56:34 am »
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
Seven Transistor Labs, LLC
Electronic design, from concept to prototype.
Bringing a project to life?  Send me a message!
 

Offline Yansi

  • Super Contributor
  • ***
  • Posts: 2529
  • Country: 00
  • STM32, STM8, AVR, 8051
Re: Microstrip bending in a transformer
« Reply #2 on: September 14, 2017, 12:04:58 pm »
Why not using a tapered transition instead of the stepped one?  Doesn't the taper give more bandwidth naturally?
 

Offline i_am_mry

  • Newbie
  • Posts: 2
  • Country: ru
Re: Microstrip bending in a transformer
« Reply #3 on: September 14, 2017, 01:29:00 pm »
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.

Quote
or 90 degree corners with a chamfer (trace length follows the inside path)



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.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf