摘要 |
<p>A external feedback network (4, 5) for decreasing variations in a beam pointing angle of a scanning antenna array. A dedicated aperture manifold (4) is integral with the aperture (1) of the scanning antenna and provides a signal which represents the beam pointing angle. The signal is detected (13), decoded (15), and converted into digital data for averaging and processing by a central processing unit a (CPU). The processed data is then compared with a value stored in memory and any difference forms the basis of a correction signal. For application to a microwave landing system, the correction signal is used to adjust the start/stop time of the scanning commands of the antenna to remove the error without modifying the beam steering algorithm. A space-coupled monitor (6,7) may also be used independent of the feedback network to provide an alarm indication in response to any failure of the dedicated aperture manifold (4), the automatic stabilization circuitry (5) or the array system (1, 2, 8, 9, 11).</p> |