Antenna system employing a self-referencing microwave interferometer for direction finding

摘要

A direction finding antenna system including a self- referencing interferometer for determining the direction of a source that emits plane wave radiation. The interferometer includes a slab of dielectric material for passing incident plane waves and for guiding coherent waves excited by the incident plane waves, whereby the guided waves interfere with the incident plane waves passing through the slab to form intensity fringe patterns, wherein the fringe spacing in a given dimension along the non- incident surface of the slab equals 2&pgr;(K.sub. g -K.sub.o sin &thgr;). sup.-1, wherein K.sub.g is the propagation constant of the dielectric material, K.sub.o is the propagation constant of free space, and &thgr; is the angle between the normal to the incident surface of the slab and the direction of the incident plane waves. The interferometer further includes an array of sensors distributed on the non-incident surface of the slab for providing sensing signals that indicate the intensity of the interfering waves at predetermined locations on the non-incident surface of the slab. The antenna system is particularly useful in a randome of a guided missile or aricraft.