Patent ID: 11901603
Assignee: BEIJING UNIVERSITY OF POSTS AND TELECOMMUNICATIONS
Field: Telecommunications (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A coupled-line rat-race coupler with smooth in-phase and out-of-phase performances, the rat-race coupler comprising:
a first port, a second port, a third port and a fourth port; and
a first coupled-line, a second coupled-line, a third coupled-line and a fourth coupled-line, each of the coupled-lines composed of a first line and a second line of metal;
wherein the first port is connected with a front end of the first line of the first coupled-line, the second port is connected with a front end of the second line of the second coupled-line, the third port is connected with a front end of the second line of the first coupled-line, and the fourth port is connected with a front end of the first line of the second coupled-line;
a back end of the first line of the first coupled-line is connected with a back end of the first line of the second coupled-line;
a front end of the first line of the third coupled-line is short circuited with a front end of the second line of the third coupled-line, a back end of the first line of the third coupled-line is connected with a back end of the second line of the second coupled-line, and a back end of the second line of the third coupled-line is connected with a back end of the second line of the first coupled-line; and
a front end of the first line of the fourth coupled-line is short circuited with a front end of the second line of the fourth coupled-line, a back end of the first line of the fourth coupled-line is open circuited, and a back end of the second line of the fourth coupled-line is connected with the back end of the first line of the first coupled-line and the back end of the first line of the second coupled-line.