Patent ID: 7964937

Claim:
A multilayer dielectric substrate that includes a cavity on a dielectric substrate, and a semiconductor device in the cavity, the cavity being an electromagnetically shielded space, the multilayer dielectric substrate comprising: a grounding conductor that is a part of the electromagnetic shield, and covers substantially the entire dielectric substrate in the cavity; an opening that is located at a part of the grounding conductor; an impedance transformer that is located in the dielectric substrate, electrically connected to the cavity through the opening, and has a length an odd number times as long as about ¼ of an in-substrate effective wavelength of a signal wave; a dielectric transmission line with an end short that is located in the dielectric substrate; a coupling opening that is located on an internal grounding conductor in a connecting section of the impedance transformer and the dielectric transmission line; and a resistor that is located at a position in the dielectric transmission line distant from the end short by a length an odd number times as long as about ¼ of the in-substrate effective wavelength of the signal wave.