90?° coupler design

HI,

I need help designing a 90deg Directional Coupler for 2-18GHz. I will be using HFSS. Has anyone done this before. Does anyone have any HFSS project files to share.

Thank you

Are you talking about a microstrip coupler?

You can try this page to get dimensions for the type of substrate you have.

h**p://people.web.psi.ch/gaspar_m/cgi-bin/mwtools/mwtools.html

S.

Thanks Sinatra,

I am looking for Microstrip or Stripline...

That link you mention is not for wideband couplers unfortunately.

You can find very good information on wideband coupler design on this book: Stripline Circuit Design by Harlan Howe, Jr edited by Artech House.

I have the book but unfortunately I don't have it in electronic format.

NandoPG

If nobody has any HFSS coupler projects, does anyone have any e-books or pdfs on the topic.

The topology you should search for is an asymmetric tandem connection of a symmetric array of coupled line.
With three coupled lines in cascade (symmetric array) tandem connected to one coupled line (asymmetric connection) you will be able to get the bandwith you need.
For synthesis of coupled line you can take a look on the book Foundaitions for Microwave Engineering by R. Collins. This book was uploaded here and the link is:
https://www.edaboard.com/viewtopic.p...ve+engineering

NandoPG

I have a question regarding the tandem connection of of two -8.34 dB couplers to create -3dB coupler.

Why is this done? Why can't a -3dB coupler be directly designed? My guess is probalby to achieve larger bandwidth or possibly to achieve 90 deg phase shift.

Any one got any comments?

The tandem method keeps the coupling low between the coupled lines in each coupler which is easier to do mechanically.

I appreaciate your response, but can you elaborate, I still don't understand why we can't do just one -3dB coupler. What do you mean 'keeps the coupling low', and 'easier mechanically'?

Hi Salem,

How Are you? I hope you are fine.
I believe that you are lookin for this Coupler.

Regards

try this website
http://www.eetc.globalsources.com/AR...RFD_AN1897.PDF

Hi guys,

Currently i am doing thesis on ultra wideband quadrature couplers... i am kinda lost...is there any good links or anyone who can offer me good advice...please drop me a msg

Thanks

I have a design for 64 MHz.

I just simulated your model. It's not a wideband coupler.

Hi,

does anyone has some experience in forward coupler design? This type should have large bandwidht.

flyhigh

The following paper discusses a coupler that I would like to make but doesnt seem to give clear instructions form a designers point of view.

"Improvements in ultra broadband TEM coupler design" IEE proceedings vol.139 No2 April 1992

Added after 1 minutes:

I forgot to attach it! Here it is.

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