Patch Antenna Fed via Unequal-Crossed-Arm Aperture

Abstract

A proposed rectangular-patch antenna for transmitting or receiving microwave circularly polarized (CP) radiation would be fed via a cross-shaped aperture that would have unequal arms and would, in turn, be fed at a single point via a microstrip transmission line. As a consequence of the unequal-arm aperture design, the antenna could be made smaller in one dimension, relative to a typical prior CP antenna that comprises a nearly square patch fed via an equal-crossed-arm aperture. Hence, in designing a phased array of such antennas, the antennas could be packed together more closely along one dimension, making it possible to scan the beam radiated by the antenna over a wider angular range in a plane that includes that dimension. Alternatively or in addition, one could lay out transmission lines in the extra spaces created by the shortening in one dimension