| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a coupler that is excellent in characteristics over a wide band and 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 ISO port on a multilayer substrate. The sub line is longer than the main line; the main line is arranged on a first layer; a first sub line part, which is a part of the sub line, is arranged on a second layer lower than the first layer; one end of the first sub line part is connected with the coupling port; a second sub line part, which is the other part of the sub line, is arranged on a third layer upper than the first layer; one end of the second sub line part is connected with the ISO port; the other end of the first sub line part and the other end of the second sub line part are connected with a via; the main line, part of the first sub line part, and part of the second sub line part are arranged such that they are adjacent or overlap when viewed from a plane surface, which forms a coupling part at each of the main line, one end of the first sub line part, and one end of the second sub line part; an intermediate part of the sub line extending between the coupling part of the first sub line part and the coupling part of the second sub line part is defined as a non-coupling part; and an intermediate ground is laid between the non-coupling part of the first sub line part and the non-coupling part of the second sub line part.</p> |
