Patent ID: 7729129

Claim:
An electronic device having a package internally incorporating at least one of a high-frequency transistor, a microwave integrated circuit (MIC), and a monolithic microwave integrated circuit (MMIC) used in a microwave to millimeter-wave band, a base thereof being formed of metal and serving as ground, and a case on which the package is mounted, comprising: two circuit boards that are mounted at circuit-board-bearing locations on the case so that the two circuit boards sandwich, a package-bearing location on the case; a package reception portion, formed at the package-bearing location, which receives the package and has a step on each of four sides, at least one step that is among the four steps and through which microwaves to millimeter-waves do not pass being inclined; and a graphite sheet that is laid on an entirety of the package reception portion and circuit-board-bearing locations, wherein the package and the graphite sheet are fastened together in the package reception portion and attached to the case by two or more screws.