Design of a microstrip multi-patch end-fired antenna for collision avoiding system of aircraft

In airborne systems, where low aerodynamic drag is urgently required, an end-fire antenna is suitable to be used. Traffic alert and Collision Avoidance System (TCAS) is an airborne electronic system that is designed as the last defense equipment for avoiding mid-air collisions of two aircraft. An effort to develop such an antenna, using microstrip elements, is described in this paper. Here, a Dual Patch Dual Feed Microstrip Antenna is presented which radiates in the end-fire direction. Thereafter, a Quad Patch Multi-Feed Microstrip Antenna is proposed and it is designed in such a way that it can radiate the whole 360° surveillance region of the aircraft. For designing these antenna models, CST Microwave Studio (MWS) is used here as the EM tool. From the simulation results, various antenna characteristics have been studied. Thereafter, these antenna prototype models have been fabricated and tested. Quite good agreement is achieved between the simulated and the measured results.