| 摘要 |
An improved control system for controlling the electrical tilt, i.e. the electrically controlled inclination of a radiated beam, of a base station antenna (70) with a vertical row of antenna elements is disclosed. The antenna includes a phase shifting device (73) including a tilt adjusting mechanism with a displaceable mechanical element for adjusting an electrical tilt setting of the antenna lobe being radiated from the antenna. The control system is divided into two parts, namely a first part, including the entire tilt adjusting mechanism (73), an electrical motor (75) and a position sensor (74), these elements constituting internal components being arranged inside the antenna casing (70), and a second part, including the remaining components of the control system, including an electrical motor control circuit (51; 61), and a logic circuit (56; 66) determining the electrical tilt setting. The external components are disposed in a separate, external control unit (50; 60) located outside but in the vicinity of the antenna casing (70), and are adapted for operative coupling, by way of a direct electric wire connection or a capacitive coupling, to the internal components (73,74,75) located inside the antenna casing.
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