| 摘要 |
<p>An antenna arrangement for use in an ultra-wideband network comprises a plurality of active monopoles. Each monopole is oriented substantially perpendicular to a ground plane, and arranged in a row along a transmission axis. Each monopole has an active portion for emitting radio signals and switch means for selectively changing the length of the active portion. Control means are provided for controlling the plurality of switch means such that, in a first configuration, the lengths of the active portion of the monopoles increase from a first end of the row towards the opposite end of the row, thereby causing radio signals to be emitted by the antenna arrangement substantially in a first direction along the transmission axis from the opposite end of the row towards the first end of the row. In a second configuration, the lengths of the active portion of the monopoles increase from the opposite end of the row towards the first end of the row, thereby causing radio signals to be emitted by the antenna arrangement substantially along the transmission axis in a direction opposite to the first direction.</p> |
