A Wideband Circular-Polarized Beam Steering Dielectric Resonator Antenna Using Gravitational Ball Lens

This communication proposes a wideband circular-polarized (CP) beam steering dielectric resonator antenna (DRA) using a gravitational ball lens. It offers a passive means for wall or ceiling mounted base station antennas to adjust their patterns by the gravity of ball lenses. This novel antenna concept overcomes the difficulties of achieving wideband axial ratio versus the pattern reconfigurability of the existing antennas. The operation of the ball lens has been intensively studied. It is found that the ball lens provides 1.2 dB antenna gain enhancement, whereas enabling beam tilting via energy coupling to the offset direction. As a demonstration, a codesign of DRA and ball lens has been developed at 2.4 GHz, achieving 42% impedance bandwidth, 39% axial ratio bandwidth, and ±40° beam steering. Reasonable agreement between simulated and measured results is observed. The proposed DRA provides a low-cost solution for base stations to be mounted at an angle and effectively cover the indoor users.