Noise Figure of an Active Antenna Array and Receiver System

Progress has been made in extending traditional antenna terms to complex phased array receivers, but a satisfactory definition for the noise figure of an active antenna and receiver system has not yet been given. This is particularly so for the case of a complex phased array with electronic gains in each signal path and beams formed using digital signal processing. We provide a simple definition for the active antenna and receiver noise figure, which is consistent with existing active antenna terms. The active antenna noise figure can be measured using the antenna Y-factor technique.