Design And Implementation Of A Traffic Alert And Collision Avoidance System Antenna For China-made Large Aircraft

Traffic Collision Avoidance System (TCAS) is an essential equipment for large homemade passenger aircraft, which is used to avoid civil aviation passenger planes colliding with each other in the air. TCAS antenna has an important role in transmitting and receiving signals, the design of which occupies an important position in the design of the whole TCAS. The traditional TCAS antenna can only radiate electromagnetic wave of 90° beam width, which is likely to lose the target when antenna receives the target signal. Once the target appears on the flight path of the aircraft, a collision may happen. Therefore, it is imperative to develop a TCAS antenna which has a built-in electrical control, can realize directional and omnidirectional radiation mode and has low profile, small size, light weight and reliable performance.In this paper, the main advantages of the design of TCAS antenna are:1. Design the Traffic Collision Avoidance System antenna for the civil aviation passenger plane in China for the first time, and the size of which decreases to nearly 1/5 of the TCAS antenna Ⅱ; 2.Integrate the feed and control network which can make antenna realize 5 kinds of beam radiation through the electrical control of antenna;3.Antenna array units are in the form of planar inverted F antennas,which broaden the bandwidth of the antenna effectively.The experimental antenna module exhibited directional VSWR less than 1.5, gain greater than+1.5dBi, from 90°to 95° beam width, side/back lobe levels less than-10dB. The experimental antenna module also exhibited Omnidirectional VSWR less than 1.5,360° beam width, and gain greater than 0 dBi. The above indexes meet the request which was put forward to our antenna according to the domestic large aircraft collision avoidance radar system. The prototype of this antenna has delivered avionics system design unit to use, and it has passed the acceptance.