How to design Rat Race Coupler using coupled line in Agilent ADS 2009
I have to design a traditional rat race coupler for (1.7 GHz-2.7 GHz) band using coupled line instead of the microstrip transmission line in Agilent ADS2009. Can any one suggest me, how should I start my work. I don't have any idea on that. It will be a great help for me. Thank You.
In a Rat-Race coupler to reduce the length of the 3λ/4 transmission line, this line can be replaced with a λ/4 coupled line.
But this results in a very low distance between coupled lines (due to the large even/odd mode impedance ratio).
Hi vfone,
Thanks a lot for your suggestion. But I would like to know how can I replace the microstrip transmission line with the coupled line? Can you please help me with any tutorial. So, that I can work with it. I am looking forward from you. Thank You.
See the attached picture how to replace a 3λ/4 with a λ/4 coupled line.
The picture is just informative, may need different microstrip T-junctions, or TL widths.

Hi Vfone,
I need to know more detail about the conversion of coupled line from microstrip line. Can you please provide me, the schematic & detail calculation for the whole process. Thank You.
"A picture is worth a thousand words"
You got the idea, you got the picture, you can start doing the homework.
