Pattern-Reconfigurable Antenna With Five Switchable Beams in Elevation Plane

Pattern-reconfigurable antennas with multiple switchable beams, especially with both boresight and endfire directions, are highly desired for wireless communications. In this letter, a novel pattern-reconfigurable antenna is proposed that provides an efficient solution. By reconfiguring parasitic striplines placed around a radiating dipole and reflecting metal pieces under the dipole using p-i-n diodes, the antenna main beam can be switched to five directions in the elevation plane, approximately from -90° (left endfire), -45°, 0° (boresight), +45°, to +90° (right endfire). The proposed antenna operates at 2.45 GHz with dimensions of about 0.57λ × 0.45λ × 0.28λ. An antenna prototype is fabricated and measured. For all five directional beams, the measured |S11| values are below -13 dB, and the measured realized gains range from 5.2 to 6.5 dBi. They agree reasonably well with the simulated ones.