Directional coupler

摘要

A directional coupler has a first line capable of transmitting a high-frequency signal therethrough and a second line arranged for electromagnetic coupling with the first line in a laminated board. The first line and the second line are routed on a first conductor layer to extend in close proximity to and in parallel with each other, to form an intra-layer coupling zone for developing electromagnetic coupling between the first line and the second line. The second line is routed on a second conductor layer such that the second line partially overlaps with the first line disposed on the first conductor layer with respect to a length-wise direction, when viewed in plan, to form an inter-layer coupling space for developing electromagnetic coupling between the second line on the second conductor layer and the first line on the first conductor layer.

主权项

1. A directional coupler comprising:
a first line capable of transmitting a high-frequency signal therethrough; a second line arranged for electromagnetic coupling with said first line; a first port disposed at one end of said first line; a second port disposed at the other end of said first line; a third port disposed at one end of said second line; and a fourth port disposed at the other end of said second line, wherein said first and second lines and said first, second, third, and fourth ports are arranged in a laminated board having a plurality of conductor layers including a first conductor layer and a second conductor layer laminated through an insulating layer, said first line and said second line are disposed on said first conductor layer, said first line and said second line are routed on said first conductor layer to extend in close proximity to and in parallel with each other, to form an intra-layer coupling zone for developing electromagnetic coupling between said first line and said second line, said second line is routed on said second conductor layer such that said second line partially overlaps with said first line disposed on said first conductor layer with respect to a length-wise direction, when viewed in plan, to form an inter-layer coupling space for developing electromagnetic coupling between said second line on said second conductor layer and said first line on said first conductor layer, said laminated board is rectangular in shape when viewed in plan, said first conductor layer and said second conductor layer are both arranged horizontally within said laminated board and each have a first corner, a second corner adjacent to said first corner, a third corner located diagonal to said first corner when viewed in plan, and a fourth corner located diagonal to said second corner, said first port is disposed at a first corner on said first conductor layer, and said third port is disposed at a second corner adjacent to said first corner on said first conductor layer, said first line extending from said first port and said second line extending from said third port extend in close proximity to and in parallel with each other to form said intra-layer coupling zone on said first conductor layer, and said first line and said second line spirally extend to each draw a spiral from a peripheral area to a central area of said first conductor layer and to each be wound more than one turn, and said first line is connected to a first via hole in the central area of said first conductor layer, and is routed to a central area of said second conductor layer through said first via hole, and said second line is connected to a second via hole and routed to the central area of said second conductor layer through said second via hole, said second port is disposed at one of said third corner and said fourth corner on said second conductor layer, and said fourth port is disposed at the other of said third corner and said fourth corner or between said third corner and said fourth corner on said second conductor layer, said first line extending from said first via hole to said second port and said second line extending from said second via hole to said fourth port extend in close proximity to and in parallel with each other to form said intra-layer coupling zone within said second conductor layer, and said first line and said second line spirally extend to each draw a spiral from a central area to a peripheral area of said second conductor layer and to each be wound more than one turn, said intra-layer coupling zone spirally extending on said first conductor layer overlaps with said intra-layer coupling zone spirally extending on said second conductor layer, when viewed in plan, such that said first line on said first conductor layer and said second line on said second conductor layer overlap with each other, while said second line on said first conductor layer and said first line on said second conductor layer overlap with each other, when viewed in plan, to form said inter-layer coupling space, in a manner that a double coupling space is formed for developing the electromagnetic coupling on the same conductor layer and the electromagnetic coupling across different conductor layers, said double coupling space is formed substantially over the entire length of said first and second lines except for an end connected to said first port, an end connected to said third port, an end connected to said second port, an end connected to said fourth port, and an end connected to said via hole, and both said first line and said second line are disposed on only said first and second conductor layers.