Apparatus and method for an amplitude monopulse directional antenna

摘要

A directional antenna suitable for use with the transmission and reception of information related to the traffic alert and collision avoidance systems (TCAS) of a monitoring aircraft is disclosed. The directional antenna includes four monopole antennas positioned and electrically coupled in a manner to produce a radiation pattern having unique directional characteristics. The disclosed antenna can transmit radiation in a directional pattern. The antenna can also receive radiation from a transponder equipped intruder aircraft (i.e., an aircraft within a predetermined range of the monitoring aircraft). By comparing the amplitudes of the signals induced in the plurality of antenna elements by the received radiation, the bearing (direction) of the intruder aircraft relative to the monitoring aircraft can be determined. The antenna is fabricated to provide a reduced cross-sectional profile, for example by providing a folded monopole antenna structure, thereby reducing the antenna profile in aircraft applications.