Beam sharpened pencil beam antenna systems.

摘要

A beam sharpened antenna pattern (40) is achieved by intercoupling signals from individual radiating elements (10-13) of an array to produce a sum mode signal (42) and a ring mode signal (44). The ring mode signal represents a forward-directed antenna pattern having a zero to 360 degree progressive phase characteristic around a pattern axis (14a). Beam sharpening results from processing the sum and ring mode signals to provide a pattern (40) having 360 degree beam sharpening, which represents portions of the sum mode pattern (42) of amplitude greater than the amplitudes of selected portions of the ring mode signal (44). The ring mode signal may be provided on a predetermined basis after selected attenuation or amplification in order to provide a beam sharpened antenna pattern having a modified characteristic. In some applications, received signals are processed on a simultaneous sum mode and ring mode basis, while during transmission pulsed sum mode and ring mode antenna patterns are activated on a sequential, timed basis. Arrangements for use of the invention with two-dimensional-scan (Fig. 4) and one-dimensional-scan (Fig. 5) phased arrays are also described. <IMAGE>