| 摘要 |
<p>An antenna system (1) comprises a directional antenna (2) adapted to rotate through a range of directions in azimuth. It is responsive to radio-frequency (RF) signals received from directions within the range of directions in azimuth. A receiver (7) is arranged to receive the RF signals from the antenna within a signal frequency response band of the receiver and to provide a corresponding output for signal processing. A signal filter (11) is operable to block the output from the receiver when the frequency of the RF signal lies at a frequency within the signal frequency response band of the receiver and a detector unit (8) is arranged to apply the signal filter when the directional antenna is directed to a predetermined azimuth at which an interference source is located and to not apply the signal filter otherwise.</p> |
