Results 51 to 60 of about 1,302 (222)

Toward Sub‐Terahertz: Space‐Time Coding Metasurface Transmitter for Wideband Wireless Communications

open access: yesAdvanced Science, 2023
A space‐time coding metasurface (STCM) operating in the sub‐terahertz band to construct new‐architecture wireless communication systems is proposed. Specifically, a programmable STCM is designed with varactor‐diode‐tuned metasurface elements, enabling ...
Yujie Liu   +12 more
doaj   +1 more source

Performance Enhancement of Reconfigurable Metamaterial Reflector Antenna by Decreasing the Absorption of the Reflected Beam

open access: yesApplied Sciences, 2021
In this study, a new concept for a Ka-band 5G communication tunable reflector metasurface (MS) for beam steering at 28 GHz is proposed. Varactor diodes are used as the tunability component of each unit cell of this MS.
Efi Rahamim   +2 more
doaj   +1 more source

Metamaterial Antennas Enhance MRI of the Eye and Occipital Brain

open access: yesAdvanced Materials, Volume 38, Issue 32, 8 June 2026.
A radiofrequency antenna platform comprising planar and bend configurations is developed, incorporating structurally integrated epsilon‐negative metamaterial unit cells to enhance MRI. These antennas enable high‐resolution in vivo human MRI of the eye, orbit, and occipital brain. Comprehensive validation, including simulations, phantom experiments, SAR,
Nandita Saha   +14 more
wiley   +1 more source

A Reconfigurable MIMO/UWB MIMO Antenna for Cognitive Radio Applications

open access: yesIEEE Access, 2019
A novel multi-mode frequency reconfigurable MIMO and an ultrawideband (UWB) MIMO antenna design for cognitive radio applications is proposed in this paper.
Xiongwen Zhao   +2 more
doaj   +1 more source

Spoof Surface Plasmon Polaritons in Terahertz Integrated Circuits

open access: yesAdvanced Photonics Research, Volume 7, Issue 5, May 2026.
Terahertz integrated circuits (THz ICs) face challenges from wavelength‐scale dimensions and parasitic effects. Spoof surface plasmon polaritons (SSPPs) provide strong confinement and enhanced near fields, enabling novel transmission and modulation mechanisms.
Xuanru Zhang, Ze Kai Wang, Tie Jun Cui
wiley   +1 more source

Frequency reconfigurable antenna based on epsilon negative transmission lines

open access: yesElectronics Letters, 2023
A novel coplanar waveguide (CPW)‐fed frequency reconfigurable antenna based on epsilon negative transmission line (ENG‐TL) is presented in this letter.
Hao‐nan Luo, Xiao‐lin Yang
doaj   +1 more source

Filtenna with Frequency Reconfigurable Operation for Cognitive Radio and Wireless Applications

open access: yesMicromachines, 2023
A reconfigurable wideband monopole antenna is introduced in this paper for cognitive radio and wireless applications. The reconfigurability was achieved by four varactor diodes embedded in the band pass filter (BPF) structure which was integrated with ...
Mahmoud A. Abdelghany   +3 more
doaj   +1 more source

Spectral characterisation of variable reactance devices [PDF]

open access: yes, 1987
Low Noise Figure communication receivers require more efficient frequency converters. Frequency conversion and multiplication processes cannot take place without the existence of harmonics in the system and the inherent property of a nonlinear element is
Fifa, Ekaterini
core  

Beam Steerable Traveling Wave Meander Line Antenna Using Varactor Diode for X-Band Applications

open access: yes, 2008
This paper presents a novel beam steerable meander line antenna with varactor diode for X-band applications. Beam steering has been achieved by loading the arms of the meander line antenna with varactor diodes.
Gokalp, Nihan   +1 more
core   +1 more source

Interactive Visualization of Diode Physics: Bridging the Fidelity‐Accessibility Gap in Web‐Based Engineering Education

open access: yesComputer Applications in Engineering Education, Volume 34, Issue 3, May 2026.
ABSTRACT In engineering education, a “fidelity‐accessibility trade‐off” persists: accessible web simulations often lack physical accuracy, while complex industrial tools impose heavy cognitive loads. This hinders effective instruction in semiconductor physics in remote, hardware‐constrained environments.
Ali Akyüz   +2 more
wiley   +1 more source

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