REDUCING COUPLING COEFFICIENT VARIATION IN COUPLERS

摘要

A number of couplers are presented that have high-directivity and low coupling coefficient variation. One such coupler includes a first trace associated with a first port and a second port. The first trace includes a first main arm, a first connecting trace connecting the first main arm to the second port, and a non-zero angle between the first main arm and the first connecting trace. Further, the coupler includes a second trace associated with a third port and a fourth port. The second trace includes a second main arm. Another such coupler includes a first trace with a first edge substantially parallel to a second edge and substantially equal in length to the second edge. The first trace includes a third edge substantially parallel to a fourth edge. The fourth edge is divided into three segments. The outer segments are a first distance from the third edge. The middle segment is a second distance from the third edge. Further, the coupler includes a second trace, which includes a first edge substantially parallel to a second edge and substantially equal in length to the second edge. The second trace includes a third edge substantially parallel to a fourth edge. The fourth edge is divided into three segments. The outer segments are a first distance from the third edge. The middle segment is a second distance from the third edge. Another such coupler includes a first trace associated with a first port and a second port. The first port is configured substantially as an input port and the second port is configured substantially as an output port. The coupler further includes a second trace associated with a third port and a fourth port. The third port is configured substantially as a coupled port and the fourth port is configured substantially as an isolated port. In addition, the coupler includes a first capacitor configured to introduce a discontinuity to induce a mismatch in the coupler.