Millimeter-wave system technologies for wireless communications, imaging, and sensing

Abstract

This paper describes millimeter-wave (MMW) system technologies for wireless communications, imaging, and sensing. MMW systems have advantages of large bandwidth and short wavelength, and recent progress in electronic and photonic device enables us to handle MMW signals easily at low cost. State-of-the-art MMW wireless communications systems can transmit over-10-Gbit/s data, and research on transmission characteristics is progressing steadily. MMW imaging systems using nearfield dispersion can achieve high resolution, and they are starting to be used for non-destructive inspections of infrastructure. An MMW sensing system based on photonic technologies enable us to cover large bandwidths and is now being investigated for remote sensing of gasses in the fields of radio astronomy and disaster prevention.

220 GHz outdoor wireless communication system based on a Schottky-diode transceiver

“…As the demand for wireless data consumption grows exponentially [1], it is a natural option to exploit the terahertz (THz) frequency band for the abundance of absolute bandwidth [2,3]. Over the past few years, THz wireless communication using electro-photonic technologies has seen impressive progress [4,5], but to adopt this approach will increase the system size because of the requirement for extra optical components.…”

Classification of terahertz spectrometer for transmittance measurements of refractive materials

“…As a result, quantitative TDS measurements are required more than ever before. Furthermore, wireless communication at 120 GHz [4] was launched in 2014, and a 300 GHz system is also under development [5]. Accurate dielectric constants of various substances in the terahertz band will be needed, and thus we consider wave properties such as propagation and absorption in various materials.…”