TWO-FREQUENCY COMMON ANTENNA SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a two-frequency common antenna system which has an excellent and stable return loss characteristic and a high gain in a high frequency band and can share frequencies of a mobile communication system even with an ordinary whip antenna.

SOLUTION: This antenna system 10 is a dipole 12 composed of dipole elements 12a and 12b of metal foils which have arbitrary widths on a dielectric substrate 11 to share two frequency bands, and characterized in that a position shifting from the geometric center point CO between both ends of the dipole elements by a certain length along the length of the dipole elements is regarded as the feed center point C of the dipole 12. The dipole 12 is made to resonate at a frequency fed from common feeders 15a and 15b through the feed center point C, the dipole element 12a which is shorter between the dipole elements is fed from the feeders through the feed center point C to make its dipole element length resonate at a frequency f2 (f2>f1), and the operation mode is set to a whip antenna.

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