| 摘要 |
PROBLEM TO BE SOLVED: To provide a small antenna for portable radio equipment, which easily corresponds to plural frequency bands and has satisfactory sensitivity, by winding a folded antenna to a circular form (ring form) so as to constitute the antenna. SOLUTION: An antenna element 12 provided for the outer periphery of an insulating cylinder (core) 11 forms a folded antenna where a folded part is formed in at least one-time shaft direction. An insulating coat 16 such as a thermally shrinking tube is covered from the upper side of the antenna element 12 and it is fixed to the insulating cylinder 11. The metallic holder 13 where a screw part 13a is formed at the outer periphery of a lower part is fixed to the lower end part of the insulating cylinder 11 so that it can be fitted to the casing of the radio equipment by press fitting. At that time, a tongue piece 12a being one end of the antenna element 12 is brought into contact with the inner wall of the holder 13 and they are electrically connected. The periphery is coated with the antenna element 12 and a protected cap 14 is screwed into the holder 13 so as to be fixed. |
