| 摘要 |
PURPOSE: To realize the antenna for an equipment for a personal communication base station capable of utilizing small power effectively and coping with diversity communication with simple configuration. CONSTITUTION: Co-linear antenna elements 17 having a directivity in which a gain of a horizontal plane is almost uniform over the entire circumference are formed as a pattern onto a front side 16a of a board 16 of an antenna 15. A spacer 18 is mounted on a rear side of the board 16 and a reflection strip plate 19 shifting forward the directivity of the horizontal plane of the antenna elements 17 in front of the board 16 by a prescribed gain is fitted longitudinally to a rear side 18a of the spacer 18 so as to be opposite to the antenna elements 17. The thickness D of the spacer 18 is selected to be nearly a multiple of 0.15 of a wavelength λ of a radio wave used for communication, and the width W of the reflecting plate 19 is selected to be nearly 1/8 of the wavelength λ so that the shift in the directivity is 2-3dB and the reduction in the gain in the side direction of the board 16 due to this shift is within 0.5dB. |
