To control the directivity of a radio device to the set directivity.
A radio-wave nontransmission part 22 is installed at an enclosure 2. The part 22 is formed of a material which absorbs radio waves radiated from a built-in antenna 10. While the radio waves radiated to the rear side from the antenna 10 are output to the outside through the rear-side part 2b of the enclosure 2, the radio waves radiated to the front side from the antenna 10 are absorbed by the part 22 and not propagated outside from the enclosure 2. When the position and the size of the part 22 are varied, the directivity of the radio waves from the antenna 10 can be controlled apparently. It is possible to easily provide the radio device which has the required directivity of the radio waves.
HIRANO SATORU
NAGUMO SHOJI
