Patent ID: 6873224

Claim:
A four port coupling device comprising a 90 degree phase shifter having ports 1 , 2 , 3 , and 4 , port 1 for receiving an input signal, and having an output appearing across ports 2 and 3 and the input appearing across ports 1 and 4 , a transmission line capacitor coupled between each port and ground, a first transformer having a first winding connected between ports 1 and 2 and a second winding connected between ports 3 and 4 , said first and second windings being coupled in phase, a second transformer having a first winding connected across port 1 and port 4 sides of said first and second windings of said first transformer respectively, a second winding connected across port 2 and port 3 sides of the first and second windings of said first transformer respectively, said windings of said second transformer being coupled in phase.