| 摘要 |
PROBLEM TO BE SOLVED: To provide an antenna by which two signals with different frequency bands are sent/received. SOLUTION: A 1st helical antenna element 20 is wound on an outer periphery of a dielectric block made of cylindrical bobbin 22 and a 2nd helical antenna element 24 is placed concentrically in the cylindrical bobbin 22. An end of the cylindrical bobbin 22 is fit-fixed to a conductor made mounting metal fittings 26 and the base ends of the 1st and 2nd helical antenna elements 20, 24 are respectively fixed to the mounting metal fittings 26 and connected thereto electrically. Then the resonance frequency of the 1st and 2nd helical antenna elements 20, 24 is set to two desired frequency bands. |
