Patent ID: 8035994

Claim:
A high frequency storing case that stores therein a plurality of high frequency circuits to be mounted on a multilayer dielectric substrate, the high frequency storing case comprising: a cavity that is formed at least by an electromagnetic shield that is obtained by electrically connecting an earth conductor that is formed on the multilayer dielectric substrate and on which the plural high frequency circuits arranged in a signal propagation direction are mounted, and a shield cover member that spatially covers the plural high frequency circuits, and that has a length in a direction perpendicular to an arrangement direction of the plural high frequency circuits, smaller than ½ of an effective wavelength in the substrate of a first signal wave generated by one of the high frequency circuits; a waveguide aperture that is formed on the earth conductor on which the high frequency circuits are mounted and that is electrically coupled to the cavity, the waveguide aperture being located within the cavity; and an end-short-circuited dielectric waveguide that is connected to the waveguide aperture, is formed in a direction of layer lamination of the multilayer dielectric substrate, and has a length approximately ¼ of an effective wavelength in the substrate of a second signal wave having a frequency N times (N=>2) higher than that of the first signal wave generated by the one of the high frequency circuits; wherein the end-short-circuited dielectric waveguide is configured by an inner-layer earth conductor, and plural through holes connected to the earth conductor and the inner-layer earth conductor.