Simultaneous Radiation of Odd and Even Patterns by a Linear Array

A method is described for obtaining, with a broadside linear array, simultaneous radiation of two antenna patterns, one of which is an odd function, and the other an even function of azimuth angle. While the two patterns are not mutually independent, it is possible for them both to be free of minor lobes. The arrangement has an appealing simplicity when used with a slotted waveguide; however, it also has the drawback that the performance is limited to a comparatively narrow band of frequencies. An approximate theory of operation is given, together with some experimental results for an application in connection with runway localizers for instrument landing.