A Pattern-Reconfigurable Antenna for Single-RF 5G Millimeter-Wave Communications

A millimeter-wave (mmWave) antenna with beam steering capability and a single feed is introduced. Fifth-generation (5G) systems with a single feed or a single radio frequency (RF) chain can provide inexpensive and energy-efficient solutions in applications such as the Internet of Things. The antenna consists of a half-wavelength dipole with a balun structure printed on both sides of a substrate and a parasitic pixel surface in front of the dipole. The antenna achieves beam-steering in the azimuth plane by controlling two diodes that alter the connections in the parasitic surface. Phase shifters or multiple feeds are not required to control the beam angle and therefore the antenna can support single-RF 5G operation. By introducing proper objective functions, the connections of the parasitic surface and locations of the two diodes can be optimized with the genetic algorithm. The ground plane and dc bias lines are printed on the backside of the substrate. Simulation and experimental results show that the proposed single port pattern reconfigurable antenna can operate in the 26–30 GHz mmWave bands. The realized gain of 7.96 dBi and two radiation patterns with peak gains directed to 75
$^{\circ }$
and 110
$^{\circ }$
are verified by experiment demonstrating the feasibility of the proposed design concept.