Japan's NTT DoCoMo and Germany's Rohde & Schwarz joined forces on a set of experiments to measure and analyze RF propagation characteristics and shielding effects in spectrum bands above 100 GHz.
Using test and measurement equipment from Rohde & Schwarz, DoCoMo developed what’s being described as a novel ultrawideband mmWave band channel sounder to measure radio wave propagation characteristics and evaluate mobile communication systems exceeding 100 GHz.
In one of the experiments, the test system was placed in an anechoic chamber. DoCoMo and Rohde & Schwarz said they were able to confirm that they can measure and analyze the shielding effect of the human body, applying signals up to 150 GHz and in 5G frequency bands that are either currently in use or under consideration.
Measurement parameters include the propagation loss (degree of attenuation of radio waves), power delay profile (arrival time of radio waves) and angular profile (indicator of spread of radio wave arrival), according to the press release.
While it might sound “way out there,” the R&D around spectrum bands above 100 GHz has been gaining steam, as wider bandwidths are available in the 100 to 300 GHz bands. But as the companies point out, the higher bands are strongly affected by persons, vehicles, trees and environmental conditions like rain, making it necessary to research the impact of such objects on the radio wave propagation characteristics.
In the U.S., work has been ongoing at the New York University Wireless research center and NYU Tandon School of Engineering’s Electrical and Computer Engineering Department, which organized a series of fall seminars featuring foremost scientists and engineers in the field of terahertz electromagnetic spectrum. Terahertz generally refers to spectrum above 100 GHz and goes all the way up to 540 GHz or so.
The FCC earlier this year launched a Notice of Proposed Rulemaking seeking comments on a plan to make the spectrum above 95 GHz more readily accessible for new services and technologies.
This past summer, representatives from the mmWave Coalition met with FCC Chief Engineer Julius Knapp and other personnel of the Office of Engineering and Technology to discuss the proceeding, urging the commission to consider rules that would accommodate both point-to-point and point-to-multipoint systems and advocating RF safety limits for frequencies above 100 GHz, among other things.
Nokia, Keysight Technologies, Qorvo and Marcus Spectrum Solutions are some of the members of the mmWave Coalition.