Conference Paper

Path-loss Characteristics and Modeling for 2-300-GHz bands in Urban Microcell Environment

March 2023

DOI:10.23919/EuCAP57121.2023.10133251

Conference: 2023 17th European Conference on Antennas and Propagation (EuCAP)

Authors:

Motoharu Sasaki

Nippon Telegraph and Telephone

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Improvement of Angular Dependence of Angular Profile in DOA Measurement Method using Rotating Reflector Antenna

Article

Jan 2024

In next-generation mobile communications, the proactive use of millimeter-wave and terahertz-wave frequencies, which can secure a wide frequency bandwidth, is anticipated. The authors reported a measurement method using a rotating reflector antenna to realize high-speed direction-of-arrival (DOA) measurement by rotating a large-aperture antenna at these frequencies. The conventional proposal method adopted a circularly polarized antenna as the primary radiator to accommodate the polarization rotation of the antenna. However, this method had the issue of angle dependency in the angular profile. To solve this problem, this paper proposes a measurement method that uses an orthogonally polarized antenna as the primary radiator of a rotating reflector antenna for rotational measurements, and processes the acquired data offline. To confirm the effectiveness of the proposed method, a demonstration experiment is conducted in an anechoic chamber, and it is shown that an angular profile with less angular dependence can be obtained than using a circularly polarized antenna as the primary radiator. We also show that the proposed method is capable of fast DOA measurement.

Wireless Communications and Applications Above 100 GHz: Opportunities and Challenges for 6G and Beyond

Article

Full-text available

Jan 2019

Frequencies from 100 GHz to 3 THz are promising bands for the next generation of wireless communication systems because of the wide swaths of unused and unexplored spectrum. These frequencies also offer the potential for revolutionary applications that will be made possible by new thinking, and advances in devices, circuits, software, signal processing, and systems. This paper describes many of the technical challenges and opportunities for wireless communication and sensing applications above 100 GHz, and presents a number of promising discoveries, novel approaches, and recent results that will aid in the development and implementation of the sixth generation (6G) of wireless networks, and beyond. This paper shows recent regulatory and standard body rulings that are anticipating wireless products and services above 100 GHz and illustrates the viability of wireless cognition, hyper-accurate position location, sensing, and imaging. This paper also presents approaches and results that show how long distance mobile communications will be supported to above 800 GHz since the antenna gains are able to overcome air-induced attenuation, and present methods that reduce the computational complexity and simplify the signal processing used in adaptive antenna arrays, by exploiting the Special Theory of Relativity to create a cone of silence in over-sampled antenna arrays that improve performance for digital phased array antennas. Also, new results that give insights into power efficient beam steering algorithms, and new propagation and partition loss models above 100 GHz are given, and promising imaging, array processing, and position location results are presented. The implementation of spatial consistency at THz frequencies, an important component of channel modeling that considers minute changes and correlations over space, is also discussed. This paper offers the first in-depth look at the vast applications of THz wireless products and applications and provides approaches for how to reduce power and increase performance across several problem domains, giving early evidence that THz techniques are compelling and available for future wireless communications.

Propagation Measurements Comparing Indoor and Outdoor Hotspot Coverage at 28, 58, and 143 GHz

Conference Paper