Results 31 to 40 of about 655,319 (295)

Space-Air-Ground Integrated 6G Wireless Communication Networks: A Review of Antenna Technologies and Application Scenarios

Sensors, 2022
A review of technological solutions and advances in the framework of a Vertical Heterogeneous Network (VHetNet) integrating satellite, airborne and terrestrial networks is presented.
Francesco Alessio Dicandia, Nelson J. G. Fonseca, Manlio Bacco, Sara Mugnaini, Simone Genovesi   +4 more
doaj   +1 more source

Real-time terahertz meta-cryptography using polarization-multiplexed graphene-based computer-generated holograms

Nanophotonics, 2020
As one of the cutting-edge technologies in advanced information science, wave-based cryptography is a prerequisite to enable a plethora of secure encrypting platforms which can be realized by smart multiplexing techniques together with suitable ...
Rajabalipanah Hamid, Rouhi Kasra, Abdolali Ali, Iqbal Shahid, Zhang Lei, Liu Shuo   +5 more
doaj   +1 more source

Fully metallic frequency selective surface (FSS) circular polarizer based on cost‐effective chemical etching manufacturing technique

Electronics Letters, 2023
This letter presents a fully metallic circular polarizer based on a bandpass frequency selective surface (FSS) that converts linear polarization (LP) to circular polarization (CP) in the Ka‐band.
Wai Yan Yong, Arjen Velkers, Andrés Alayón Glazunov   +2 more
doaj   +1 more source

Visualizing nanometric structures with sub-millimeter waves

Nature Communications, 2021
The authors demonstrate a far-field approach for height profile measurements with sub-millimetre waves. By evaluating Fabry-Pérot oscillations within surface-structured samples, combined with a Hilbert-transform approach, they visualize structures with a
Alonso Ingar Romero, Amlan kusum Mukherjee, Anuar Fernandez Olvera, Mario Méndez Aller, Sascha Preu   +4 more
doaj   +1 more source

Double-layer geodesic and gradient-index lenses

Nature Communications, 2022
A double-layer lens consists of a first gradient-index/geodesic profile in an upper waveguide, partially surrounded by a mirror that reflects the wave into a lower guide where there is a second profile. A family of such lens profiles are derived.
Qiao Chen, Simon A. R. Horsley, Nelson J. G. Fonseca, Tomáš Tyc, Oscar Quevedo–Teruel   +4 more
doaj   +1 more source

Orthogonal Versus Zero-Forced Beamforming in Multibeam Antenna Systems: Review and Challenges for Future Wireless Networks

IEEE Journal of Microwaves, 2021
Orthogonality in multibeam antennas is revisited. The difference between orthogonal beamforming and zero-forced beamforming is highlighted. The intriguing relation between orthogonality, reciprocity and losses is recapitulated.
Yanki Aslan, Antoine Roederer, Nelson Fonseca, Piero Angeletti, Alexander Yarovoy   +4 more
doaj   +1 more source

A millimetre wave, quasi-optical complex impedance bridge [PDF]

, 2015
This thesis describes the work undertaken in the design and construction of a millimetre wave, quasi-optical impedance bridge. The instrument operates as a nulling complex reflectometer, with nulling being implemented at the signal frequency by ...
Harvey, Andrew R.
core   +2 more sources

Intelligent wireless walls for contactless in-home monitoring

Light: Science & Applications, 2022
This work proposes a concept of intelligent wireless walls (IWW) to ensure high-precision activity monitoring in complex environments, namely corridor junction scenario and multi-floor ...
Muhammad Usman, James Rains, Tie Jun Cui, Muhammad Zakir Khan, Jalil ur Rehman Kazim, Muhammad Ali Imran, Qammer H. Abbasi   +6 more
doaj   +1 more source

Salmonella lipopolysaccharide‐containing supported lipid bilayers as platforms to study bacteriophage interactions

FEBS Letters, EarlyView.
We present robust protocols for the preparation of supported lipid bilayers (SLBs) incorporating either Salmonella smooth LPS or outer membrane vesicles (OMVs). We use a combination of quartz crystal microbalance with dissipation (QCM‐D) and fluorescence microscopy to both characterize the SLBs of various compositions and to probe their interactions ...
Hudson P. Pace, Alyssa Borges, Charles Arnaud, Tove Karlsson, Nina K. Bröker, Stefanie Barbirz, Marta Bally   +6 more
wiley   +1 more source

Analysis of millimetre-wave polarization diverse multiple-input multiple-output capacity [PDF]

Royal Society Open Science, 2015
Millimetre-waves offer the possibility of wide bandwidth and consequently high data rate for wireless communications. For both uni- and dual-polarized systems, signals sent over a link may suffer severe degradation due to antenna misalignment ...
Nicholas P. Lawrence, Brian W.-H. Ng, Hedley J. Hansen, Derek Abbott   +3 more
doaj   +1 more source