4 port Quadrature Hybrid Coupler convert to 2port

Hi,

May I know if it is possible to convert 4 port Quad Hybrid coupler to 2 ports.
I mean can we combine, Port 1 and Port 4 as "input port", Port 2 and Port 3 as "output port"?
If yes, may I know how the output looks like or how the circuit behaves as?

Thanks.

This would be equivalent to a superposition of exciting ports 1 and 4, while simultaneously taking the output to be a superposition of ports 2 and 3.

As can easily be determined analytically, this is simply equivalent to a quarter-wavelength section of transmission line.

What are you hoping to accomplish with this?

Thanks for the reply.
The reason is I want to connect two printed folded dipole antenna back-to-back. Instead of using Isolator (which cant be built as microstrip) to protect the antenna, I am using coupler.
But the problem is how to the feed printed folded dipole? As we are using Printed folded dipole, the feed is CPL.
Can I connect Port 1 and Port 4 to feeds of dipole 1 and Port 2 and 3 to feed of Dipole 2 with microstrip to CPL transition?
Another way I though was to combine Port 1 and Port4 and use microstrip to CPL transition and then feed the dipole 1. Similarly for port 2 and 3 for feed of dipole 2.


Please share links which may be helpful.

Thanks.

What do you mean by "back-to-back" in this case?

Can you not just use a 1:4 Wilkinson power divider, and put a 180 phase delay line on two of the branches (in addition to something like quarter-wave matching sections)?