Patent ID: 8154364

Claim:
A high-frequency transmission line comprising: a dielectric substrate, a signal line disposed on one surface of said dielectric substrate, a first and a second surface ground patterns disposed on said one surface of said dielectric substrate and on both sides of said signal line, separated from said signal line with a given distance, a backside ground pattern disposed on another surface of said dielectric substrate, and a plurality of contacts penetrating said dielectric substrate to connect said first and said second surface ground patterns and said backside ground pattern; wherein a sum of the shortest distance from any point of the first and second surface ground patterns to the nearest one of said plurality of contacts and a thickness of said dielectric substrate is shorter than ¼ of an effective wavelength of a transmission signal corresponding to an effective permittivity of said dielectric substrate in a given frequency range, wherein a plurality of notches of any shape are formed on each side near said signal line of said first and second surface ground patterns in succession along the length of said first and second surface ground patterns.