| 摘要 |
PURPOSE:To enable to select the circular and horizontal polarization characteristics, by combining the sleeve having slots to one pole antenna element and switching the power feed lines. CONSTITUTION:The sleeve antenna 55 folding externally the sleeve 3 is formed by taking the antenna element 4 as a center and the slot antenna 56 consisting of the slot 2 provided on the sleeve 3 is formed. When the power feed points P1, P2 are selected so that the phase of power feed current of the power feed points P1, P2 of the antenna 56 is shifted by 90 deg. to the phase of the power feed current of the antenna 55, the antenna unit 1 shows the circular polarization characteristics to all the directions. The antenna section 56 is formed by containing the element 4 in the sleeve 3, but no power feed is made to the sleeve 3 and the antenna section 56 is not formed and the unit 1 shows the horizontal polarization characteristics to all the directions. |
