Circularly Polarized Patch Antenna with Sector Radiation Pattern

Recently, we have shown that by properly arranging two concentric patch antennas excited with different radiating modes, it is possible to generate an electromagnetic field with an anomalous polarization state, resembling the structure of a Mobius strip. In this contribution, we expand this finding by considering a single radiating structure consisting of an inner circular patch excited at its fundamental mode and an outer circular ring excited with a TM
₃₁
mode, both operating in circular polarization. Through an analysis based on the phase singularities of composite vortices, we show the possibilities for pattern shaping offered by this configuration. In particular, we demonstrate that the radiation pattern can be properly tailored to emulate that of a bulkier structure, i.e. a dipole placed at a quarter of wavelength from a reflector, thus, obtaining, a sector radiation pattern.