High-frequency substrate and high-frequency module

A high-frequency substrate in which a coplanar line comprising a signal line which transmits a signal and a pair of front ground patterns disposed in parallel with the signal line interposed therebetween is formed on one surface of a dielectric substrate, a back ground pattern is formed to cover the other surface of the dielectric substrate, and a plurality of conductive vias which connect the front ground patterns to the back ground pattern are arranged at a predetermined interval, the high-frequency substrate comprising:

• a signal line breaking portion which breaks the signal line;
• a substantially rectangular parallelepiped signal-line capacitor which is formed to connect the breaking ends of the signal line to each other;
• and
• conductive members which are disposed in the front ground pattern on both sides of the signal line breaking portion of the signal line so as to have substantially the same shape as the signal-line capacitor.

A high-frequency module having a high-frequency substrate in which a coplanar line comprising a signal line which transmits a signal and a pair of front ground patterns disposed in parallel with the signal line interposed therebetween is formed on one surface of a dielectric substrate, a back ground pattern is formed to cover the other surface of the dielectric substrate, and a plurality of conductive vias which connect the front ground patterns to the back ground pattern are arranged at a predetermined interval, the high-frequency module comprising:

• a high-frequency substrate comprising
• a signal line breaking portion which breaks the signal line,
• a substantially rectangular parallelepiped signal-line capacitor which is formed to connect the breaking ends of the signal line to each other, and
• ground pattern breaking portions which are disposed on both sides of the signal line breaking portion of the signal line to break the front ground patterns;
• and
• a semiconductor integrated circuit chip which is built in the high-frequency substrate.