| 摘要 |
PROBLEM TO BE SOLVED: To avoid an adverse effect on a UHF band radio wave reception by receiving good a VHF band low-pass side when the UHF and VHF band radio waves are received. SOLUTION: In a multiple-frequency-band antenna, extended elements 24a, 26a are extended from both the ends of a dipole antenna 4a toward an exterior. The entire length of the dipole antenna 4a is selected to a length which can receive the UHF radio wave. The entire lengths of the extended elements 24a, 26a and the dipole antenna 4a are selected to the length which can receive a VHF band high-pass region. Opening and closing elements 30a, 38a which are opened in the UHF band radio wave receiving time and closed in the VHF band high-pass region receiving time are provided between both the ends of the dipole antenna 4a and the extended elements 24a, 26a. A dipole antenna 400a of a contracted shape which can receive the VHF band low-pass radio wave is disposed in parallel with the dipole antenna 4a, and has a plurality of elements in which the length is selected to the length operating as a non-radiator, a non-wave director and a non-reflector in the UHF band. A band switching unit 464a outputs the received signal of the dipole antenna 4a at the UHF band and VHF band high-pass region receiving time and outputs the received signal of the dipole antenna 400 in the UHF band low-pas region receiving time. COPYRIGHT: (C)2005,JPO&NCIPI
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