Millimeter-Wave and Terahertz OAM Discrete-Lens Antennas for 5G and Beyond

The incoming 5G and beyond 5G wireless communications provide unprecedented ultra-high-speed transmission data rates. This is enabled by driving the carrier frequency up to millimeter-wave (mmWave) and terahertz (THz) bands and developing advanced multiplexing technology to increase spectrum bandwidth and spectral efficiency. In this article, we present novel discrete lens antenna designs to solve the two leading open challenges of orbital angular momentum (OAM) applications in mmWave and THz bands: OAM multiplexing and the diffractive problem of OAM waves. For discrete lens antennas operating at THz frequencies, the emerging 3D printing technology and its superior geometric flexibility are utilized to design and implement OAM antennas. The successful demonstration of the mmWave and THz OAM discrete lens antennas can open avenues for future several-hundred-gigabits-per-second wireless communications.