Patent ID: 7009467

Claim:
A multilayer coupled-lines directional coupler of the quarter wavelength type comprising a first, a second and a third conductive layer, being essentially planar, essentially parallel and located at a distance from each other, the second conductive layer being located between the first and the third conductive layer, the first and the second conductive layer being joined by means of at least one intermediate dielectric layer and the second and the third conductive layer also being joined by means of at least one intermediate dielectric layer, wherein, that the first conductive layer comprises a first and a second conductive strip, with extended shapes, in a conductive material, separated, essentially mutually parallel, each in one end connected to a first output and each in another end connected to a second output, that the second conductive layer comprises a third conductive strip, with an extended shape, in a conductive material, essentially parallel to the first and the second conductive strip, in one end connected to a third output and in another end connected to a fourth output, that the third conductive layer comprises a first ground plane, and that the first conductive layer comprises a fourth conductive strip, with an extended shape, in a conductive material, located between the first and the second conductive strip, in one end connected to the third output, and in another end connected to the fourth output.