| 摘要 |
PROBLEM TO BE SOLVED: To provide a coupler that has excellent characteristics not only in a forward direction but also in a backward direction across a wide band with a simple structure, and that is small in size and short in height.SOLUTION: A coupler comprises a main line, a sub line, an input port, an output port, a coupling port, and an isolation port. The sub line includes: a first coupling part having strong coupling with the main line; a second coupling part that is weak in coupling and formed closer to a coupling port side than the first coupling part; a third coupling part that is weak in coupling and formed closer to an isolation port side than the first coupling part; a first non-coupling part that is a non-coupling part extending between the first coupling part and the second coupling part and having a length of a quarter of λ or more; and a second non-coupling part that is a non-coupling part extending between the first coupling part and the third coupling part and having a length of a quarter of λ or more. |
