An introduction to wideband, two-channel direction-finding systems. I - General system overview, radiator, and arithmetic subsystems

It is pointed out that two-channel monopulse direction-finding (DF) systems have been used for many years in such antiradiation homing (ARH) missiles as Shrike and Standard ARM. The present investigation is concerned with the fairly broad topic of two-channel monopulse DF techniques. The entire system is considered in a system overview, and the design of multifilament spirals, with emphasis on dual-mode four-arm spirals, is discussed. Attention is given to radiation impedances and reference surface rotation, the hyperbolic spiral antenna, polarization diversity multimode antennas, and arithmetic subsystems.