A signal processing unit comprising: a signal processor including an oscillator that is configured to output oscillation signal, the signal processor being configured to process signal whose frequency is higher than a specific threshold; a substrate having a ground component, the signal processor being disposed on the substrate; and a conductive housing electrically connected to a first site of the ground component and to a second site that is different from the first site, the second site being located at the ground component or being an open end of an extension line another end of which is electrically connected to the housing, characterized in that the housing is configured such that a first area of the housing overlaps at least part of a second area of the housing, the first area being in a position that is an odd-numbered multiple of 1/4 wavelength of the oscillation signal away along the surface of the housing from the first site, the second area being, when the second site is located at the ground component, in a position that is an even-numbered multiple of 1/4 wavelength of the oscillation signal away along the surface of the housing from the second site, or, when the second site is the open end of the extension line, in a position that is an odd-numbered multiple of 1/4 wavelength of the oscillation signal away along the extension line and the surface of the housing from the second site. a signal processor including an oscillator that is configured to output oscillation signal, the signal processor being configured to process signal whose frequency is higher than a specific threshold; a substrate having a ground component, the signal processor being disposed on the substrate; and a conductive housing electrically connected to a first site of the ground component and to a second site that is different from the first site, the second site being located at the ground component or being an open end of an extension line another end of which is electrically connected to the housing, characterized in that the housing is configured such that a first area of the housing overlaps at least part of a second area of the housing, the first area being in a position that is an odd-numbered multiple of 1/4 wavelength of the oscillation signal away along the surface of the housing from the first site, the second area being, when the second site is located at the ground component, in a position that is an even-numbered multiple of 1/4 wavelength of the oscillation signal away along the surface of the housing from the second site, or, when the second site is the open end of the extension line, in a position that is an odd-numbered multiple of 1/4 wavelength of the oscillation signal away along the extension line and the surface of the housing from the second site. the first area being in a position that is an odd-numbered multiple of 1/4 wavelength of the oscillation signal away along the surface of the housing from the first site, the second area being, when the second site is located at the ground component, in a position that is an even-numbered multiple of 1/4 wavelength of the oscillation signal away along the surface of the housing from the second site, or, when the second site is the open end of the extension line, in a position that is an odd-numbered multiple of 1/4 wavelength of the oscillation signal away along the extension line and the surface of the housing from the second site.