| 摘要 |
PROBLEM TO BE SOLVED: To obtain desired directivity without shifting the position of an antenna by composing a crank-shaped linear antenna of an even number of lateral components and more than one longitudinal element and setting the length of each element within a specific range for wavelength. SOLUTION: This antenna has linear conductor has >=2 folding points and consists of an even number of lateral elements 2 and more than one longitudinal element 1, and the lateral elements all have equal length H satisfying 0.45λ<=H<=0.55λ, whereλis the wavelength. When the length V of the longitudinal elements 1 is so set that 0.35λ<=V<=0.45λ, the phase of an electromagnetic wave is delayed more at an element farther from a feed point 6 than at a closer element, so the directivity of the whole antenna faces down below the horizontal and slants to a reference surface. When the length V of the longitudinal elements 1 is set to 0.55λ<=V<=0.65λ, the phase of the electromagnetic wave is advanced more at an element farther from the feed point 6 than at a closer element and the directivity of the whole antenna slants to the opposite side from the reference surface. In either case, the tilt angle is larger and larger as the number of antenna elements is increasingly larger.
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