A Hybrid Antenna-Metasurface Architecture for mmWave and THz Massive MIMO.

Future millimeter wave (mmWave) and terahertz (THz) communication and sensing systems will likely rely on arrays with massive numbers of elements for beamforming and spatial multiplexing. Building such arrays in traditional active architectures (either RF or digital phase shifting) is enormously challenging from a power consumption standpoint. In this paper, we consider a transmit array architecture for mmWave and THz massive MIMO, that requires much less hardware resources and power consumption. We show that transmit arrays consisting of a small active array and a passive metasurface exhibit the ability to generate steerable highly directional beams, which enables fundamental requirements for mmWave and THz MIMO systems. We describe a flexible ultra-thin metasurface using a C-shape split ring resonator (SRR) for near-field phase correction. Simulated results demonstrate a decent high-gain pencil beam creation and good beam-steering capability by employing a compact active phased array integrated with a large-size conformal passive metasurface.