Toward Sub‐Terahertz: Space‐Time Coding Metasurface Transmitter for Wideband Wireless Communications

Abstract

A space‐time coding metasurface (STCM) operating in the sub‐terahertz band to construct new‐architecture wireless communication systems is proposed. Specifically, a programmable STCM is designed with varactor‐diode‐tuned metasurface elements, enabling precise regulation of harmonic amplitudes and phases by adjusting the time delay and duty cycle of square‐wave modulation signal loaded on the varactor diodes. Independent electromagnetic (EM) regulations in the space and time domains are achieved by STCM to realize flexible beam manipulations and information modulations. Based on these features, a sub‐terahertz wireless communication link is constructed by employing STCM as a transmitter. Experimental results demonstrate that the STCM supports multiple modulation schemes including frequency‐shift keying, phase‐shift keying, and quadrature amplitude modulations in a wide frequency band. It is also shown that the STCM is capable of realizing wide‐angle beam scanning in the range of ±45o, which offers an opportunity for user tracking during the communication. Thus, the STCM transmitter with high device density and low power consumption can provide low‐complexity, low‐cost, low‐power, and low‐heat solutions for building the next‐generation wireless communication systems in the sub‐terahertz frequency and even terahertz band.

Terahertz bi-functional polarization converter based on interference mechanism supported by diatomic metasurfaces

“…Metasurfaces, as artificially designed ultrathin electromagnetic interfaces, exhibit unparalleled modulation at subwavelength scales, including for amplitude, phase, and polarization [9][10][11][12][13][14][15]. Meta-optical systems based on metasurface configurations for manipulating the interaction between light and matter are expected to enable miniaturized, lowprofile optical assemblies that can have tremendous applications in imaging [16][17][18], communication systems [19][20][21], optical manipulation and sensing [22][23][24]. Not only that, the freedom to tailor the phase of the polarization state carried by the incident electromagnetic wave enables the metasurface to be a promising candidate for integrating multiple shaping functions into a single meta-platform [25].…”

Broadband spin-decoupled metasurface for independent wavefront manipulations of orthogonal circularly-polarized waves

“…The remarkable modulation capabilities of metasurfaces for electromagnetic waves underlie their diverse applications in radio frequency, microwave, terahertz and optical domains, for instance, anomalous reflection/refraction [4,5], focusing lenses [6], vortex wave carrying orbital angular momentum (OAM) [7][8][9], meta-holograms [10][11][12] and information encryption [13,14], etc. The development of multi-functional or multi-tasking metasurface based on the multiplexing technology represents an inevitable trend, promising widespread application prospects in wireless communication [15][16][17], stealth technology [18][19][20][21], radar systems [22,23], and various other fields.…”