Patent ID: 8258889

Claim:
A directional coupler with at least three lines and at least three ports for the directional transmission of high-frequency signals, wherein a first line and a second line are connected in a conductive manner at least at their two ends, wherein: a third line is arranged between the first line and the second line, the third line is coupled in an electromagnetic manner to the first line and to the second line, so that the high-frequency signal is transmitted from the first and second line to the third line, and the coupling of the third line to the first line and the second line is implemented via at least one coupling gap, wherein the third line is connected in a conductive manner to a fourth line and a fifth line at least at ends thereof, the fourth line and the fifth line are arranged parallel to the third line, and the fourth line or respectively the fifth line extend on the side of the first line or respectively the second line facing away from the third line, and that the fourth line and the fifth line is separated by coupling gaps from the first line and the second line, wherein the directional coupler is constructed using stripline technology, wherein: the directional coupler is constructed on a front side of a substrate, a rear side of the substrate is metallized, the metallized rear side of the substrate is disposed at a reference potential, the connections of the third line to all of the lines connected to it in a conductive manner are realized by through-contacts to the substrate rear side, wherein the through-contacts are connected in a conductive manner, and the metallization of the substrate rear side is interrupted around the connections of the through-contacts.