One- and Two-Dimensional Beam-Switching Antenna for Millimeter-Wave MIMO Applications

One- (1-D) and two-dimensional (2-D) beamforming is presented for a planar dipole antenna operating at millimeter-wave bands. 1-D beamforming was achieved by using mu (mu) -near-zero (MNZ) metamaterial slabs that were integrated in the dipole antenna, where each slab was loaded with an array of low refractive-index unit-cells. The resulting radiated beam can be scanned by 35 degrees due to the phase shift in the beam introduced by its interaction with the metamaterial slabs. In addition, the proposed antenna configuration provides gain improvement of 8 dB as the slabs effectively increase the aperture size of the antenna. An array of MNZ inclusions in the E-plane of a double dipole antenna is shown to provide scanning from -35 degrees to + 35 degrees with respect to the end-fire direction over 57-64 GHz. 2-D beam-scanning was realized by increasing the number of MNZ unit-cells in the elevation plane of double dipole antenna. Loading the slabs in front of the double dipole antenna with 10 x 7 array of MNZ unit-cells is shown to provide a beam deflection of 35 degrees in both the azimuth and elevation planes.