Results 71 to 80 of about 2,907 (204)
Review of millimeter‐wave and terahertz near‐field synthetic aperture radar imaging technology
InfoScience, EarlyView.Abstract This paper comprehensively reviews the development of millimeter‐wave (MMW) and terahertz (THz) near‐field imaging technologies, with an emphasis on the state of synthetic aperture radar (SAR)‐based imaging technologies. Near‐field imaging technologies are categorized into passive and active imaging modes, among which active imaging is favored
Qi Yang +3 more
wiley +1 more source
Optimal Hybrid Beamforming Design for Millimeter-Wave Massive Multi-User MIMO Relay Systems
IEEE Access, 2019 As a promising technology in the next generation mobile network, millimeter-wave (mmWave) communication can mitigate the spectrum crunch of improving the network capacity by exploiting the large underutilized spectrum bands of the mmWave frequencies. The
Yang Zhang +4 more
doaj +1 more source
Non‐Uniform Programmable Photonic Waveguide Meshes
Laser &Photonics Reviews, EarlyView.Integrating defect cells into uniform hexagonal waveguide meshes overcomes the fundamental spectral and temporal limitations of programmable photonics. By leveraging the Vernier effect through non‐uniform coupled cavities, this architecture achieves a tenfold increase in free spectral range and ultra‐fast sampling times, paving the way for next ...
Cristina Catalá‐Lahoz, José Capmany
wiley +1 more source
International Journal of Satellite Communications and Networking, EarlyView.ABSTRACT Low Earth Orbit (LEO) satellite communication systems have evolved into a critical component of global broadband networks, enabling wide‐area connectivity, IoT services, and intelligent multilayer satellite–terrestrial integration. Despite rapid advancements in constellation deployment, routing mechanisms, resource management, and LEO–5G/6G ...
Wei‐Hao Su +2 more
wiley +1 more source
Hybrid Beamforming: Where Should the Analog Power Amplifiers Be Placed? [PDF]
ICASSP 2019 - 2019 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 2019 5 pages, 2 figures, accepted for presentation at ICASSP ...
Yasemin Karacora +2 more
openaire +2 more sources
International Journal of Satellite Communications and Networking, EarlyView.ABSTRACT The integration of low Earth orbit (LEO) satellite constellations with commercial aircraft communication systems presents critical challenges in maintaining continuous connectivity during dynamic flight conditions. Current geostationary satellite systems suffer from high round‐trip latency (>$$ > $$ 500 ms) and inadequate coverage at high ...
Raúl Parada +4 more
wiley +1 more source
Off-broadside main beam design for frequency invariant beamformers [PDF]
, 2008 In a previously proposed design method for frequency invariant beamforming, the design for the case of an off-broadside main beam is not satisfactory.
Stephan Weiss +3 more
core +1 more source
天地一体化信息网络, 2021 Due to the characteristics of low earth orbit (LEO) communication satellite system like low propagation loss, small propagation delay and high pointing accuracy, a hybrid architecture-“analog beamforming stage and digital beamforming (DBF) stage” was ...
Rong HU +6 more
doaj +2 more sources
International Journal of Satellite Communications and Networking, EarlyView.ABSTRACT Low Earth Orbit (LEO) satellite constellations offer unprecedented opportunities for global broadband connectivity but pose significant beamforming challenges due to rapid platform motion and stringent onboard hardware constraints. Fully digital architectures, while optimal in theory, remain impractical for satellite payloads, motivating ...
Mohammad Momani +2 more
wiley +1 more source
Analog-Digital Beamforming for Tunable-Load MIMO by Mutual Coupling Exploitation [PDF]
, 2017 In this paper, we propose a joint analog-digital (AD) beamforming scheme that exploits the mutual coupling effect to further improve the performance of multi-user multiple-input single-output (MU-MISO) systems.
Sellathurai, M +8 more
core +1 more source