Vector control for airborne phased array radar

Active electronically scanned phased array radars have been identified as the `next generation´ radars for many applications and demonstrator systems have been produced over the last few years for naval, ground based and airborne applications. 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. The key to this operational flexibility and improved performance is the accurate control of the gain and phase (i.e. vector control) of the transmitted or received signal, carried out in each of the many transmit-receive (T/R) modules that comprise the active antenna face. This paper discusses the implementation aspects of gain and phase control in the T/R modules with particular reference to the requirements for active airborne phased-array radar