| 摘要 |
PROBLEM TO BE SOLVED: To obtain excellent sensitivity even when intervals of antenna patterns are made narrow for installation in a small space by arraying antenna elements in parallel and connecting them together in common at one end side for a 1st antenna conductor, and forming a 2nd antenna conductor in a semiloop shape surrounding the 1st antenna element. SOLUTION: First to sixth antenna elements e1 to e6 are for medium waves for AM broadcast waves and arranged on the rear side glass plate 1 of an automobile within an interval of 32 to 45 mm to secure a visual field. The 2nd antenna conductor 2 is for high frequencies such as FM broadcast waves and' connected to the 1st antenna element e6 and then electrically connected to the antenna elements e1 to e6 to improve the sensitivity to medium waves. The length from a 1st feed point 4 to the tips of the antenna elements e1 to e6 via the 2nd antenna conductor 2 is set to (λM/4)×K to 2(λM/4)×K, whereλM is the wavelength at the center frequency of the FM broadcast band. Here, K is the shortening rate of the glass antenna and 0.64.
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