| 摘要 |
<p>An auxiliary secondary surveillance radar antenna (2) is intended for use with a main antenna (1) which is capable of being operated in sum and difference modes. The auxiliary antenna (2) augments the difference pattern so as to reduce the likelihood of undesirable signal break through at angles away from the main boresight (6) of the radar. The auxiliary antenna consists of two monopole radiators (10, 11) which are fed in anti-phase and which are provided with suitable reflectors (19) or directors (22), so as to modify in azimuth their radiation patterns. The power fed to each monopole radiator is accurately arranged such that the energy radiated by them exactly coincides in the boresight direction of the radar, but as substantially non-zero values at other directions.</p> |
