Circularly Polarized Beam-Steering Antenna Composed of Metacurl and Metaloop Elements

A circularly polarized (CP) antenna is investigated for steering its CP beam at two different frequencies. The antenna is composed of metamaterial curl (metacurl) and metamaterial loop (metaloop) elements. The antenna height is extremely small: approximately 0.01 wavelength at the lowest operating frequency. The metacurl element radiates a CP broadside beam and the metaloop element radiates a CP conical beam. A tilted beam is formed at two different frequencies by exciting both the metacurl and metaloop elements. It is revealed that the tilted beam is moved in the azimuth plane by changing the phase of the excitation voltages for the metacurl and metaloop elements.