Transmit/receive modules for X-band airborne radar

The demands for increased radar performance and the need to cope with increasingly complex threat environments have driven the development of active phased arrays for ground based, naval and airborne radar systems. For airborne systems, advantages come from the beam pointing ability of electronic scanning which allows flexible and efficient scan volume coverage and interleaved mode operation (e.g. simultaneous search, multiple track and terrain avoidance) along with dynamic beam pattern shaping for optimisation in each operational mode. Additional system benefits, such as enhanced reliability and reduced radar cross section, are also demonstrated in such antennas. A typical active array antenna consists of hundreds or thousands of transmit/receive (T/R) modules arrayed to form a complete antenna. This paper discusses the implementation aspects of X-band T/R modules with particular reference to the AMSAR (Airborne Multirole Solid state Active array Radar) programme which was undertaken by GTDAR (GEC Thomson DASA Airborne Radar EEIG).