Results 101 to 110 of about 84,127 (307)

The study of the ground plane effect on a Multiband PIFA Antenna by using Genetic Algorithm and Particle Swarm Optimization

open access: yesJournal of Microwaves, Optoelectronics and Electromagnetic Applications
The ground plane plays an important role on the performance of a planar inverted-F antenna (PIFA). In this regard, the ground plane modification using slots is proposed in this research to obtain a dual band antenna for WiMAX application.
L. Wakrim, S. Ibnyaich, M. M. Hassani
doaj   +1 more source

Reconfigurable wideband patch antenna for cognitive radio [PDF]

open access: yes, 2009
Cognitive radio communication is envisaged to be a new paradigm of methodologies for enhancing the performance of radio communication systems through the efficient utilization of radio spectrum.
AbuTarboush, H.F.   +9 more
core   +2 more sources

Dual-band HF-UHF RFID tag antenna

open access: yesElectronics Letters, 2009
A dual-band HF and UHF RFID tag antenna with two feeding points is presented, fabricated and measured. A convenient HF resonance is obtained with an HF ASIC chip as well as good impedance matching with UHF ASIC chip in the European RFID UHF band. Tuning techniques of the design parameters are proposed, and tag performance in both frequency bands is ...
Iliev, P.   +3 more
openaire   +1 more source

Enhancing CoFe Catalysts with V2CTX MXene‐Derived Materials for Anion Exchange Membrane Electrolyzers

open access: yesAdvanced Functional Materials, EarlyView.
MXene dervied CoFe composites show increased initial Oxygen Evolution Reaction (OER) activity compared to the pure CoFe and MXene in an Anion Exchange Membrane device. Vanadium vacancies in the MXene plays a role in increased OER activity and hinders Fe leaching in the AEM device over using the pure V2C MXene as a support material for the CoFe ...
Can Kaplan   +16 more
wiley   +1 more source

Design Study of Normal Mode Helical Antenna with Dual-Frequency and Circular Polarization Used in Mobile

open access: yesJournal of Engineering and Sustainable Development, 2013
In this paper, a compact and low profile internal normal mode helical antenna with dual-frequencies and circular polarization has been proposed. The proposed antenna shows a wider operating bandwidth and it easy to cover the GSM band(890-960 MHz) for ...
Sadiq Kadem Ahmed
doaj  

Design and Investigation of Differential-Fed Ultra-Wideband Patch Antenna with Polarization Diversity [PDF]

open access: yes, 2016
A novel single- or dual-polarized ultra-wideband (UWB) patch antenna fed by coupled feeding mechanism is proposed. The single-polarized antenna consists of a square ring patch and two ?-shaped patches which are coupled to the radiating patch.
Gao, Steven, Wang, Yanfang, Zhu, Fuguo
core   +2 more sources

Engineering Porous Hollow Metal‐Poly(Heptazine Imide) Spheres: An Optimized Synthetic Strategy for Controlling Surface, Morphology, and Properties

open access: yesAdvanced Functional Materials, EarlyView.
Hollow poly(heptazine imide) spheres are prepared through a novel approach that integrates hard templating with ionothermal synthesis. This method enables precise control over surface area, pore volume, hydrophilicity, light absorption, band position, and metal composition. These tunable properties facilitate the customized design of semiconductors for
Lingli Ni   +10 more
wiley   +1 more source

Enhancing Direct Solar Water Splitting via ALD of Multifunctional TiO2/Pt Nanoparticle Coatings With Engineered Interfaces to GaAs/GaInP Tandem Cells

open access: yesAdvanced Functional Materials, EarlyView.
Multifunctional atomic layer deposited coatings and interface treatments enhance direct solar water splitting on GaAs/GaInP tandem cells. Optimized TiO2/Pt nanoparticle bilayers ensure durability and catalytic efficiency with minimal optical losses, while H2 plasma pretreatments maximize photovoltage and interfacial charge extraction.
Tim F. Rieth   +8 more
wiley   +1 more source

Dual band printed antenna [PDF]

open access: yes, 2009
The invention consists of a dual band printed antenna planned to be implemented preferably in base stations of dual mobile telephony which use GSM and DCS-1800 systems, although other applications are not rejected.Similarly to the well-known printed ...
Sánchez Hernández, David Agapito
core   +1 more source

Micropatterned Biphasic Printed Electrodes for High‐Fidelity on‐Skin Bioelectronics

open access: yesAdvanced Functional Materials, EarlyView.
Micropatterned biphasic printed electrodes achieve unprecedented skin conformity and low impedance by combining liquid‐metal droplets with microstructured 3D lattices. This scalable approach enables high‐fidelity detection of ECG, EMG, and EEG signals, including alpha rhythms from the forehead, with long‐term comfort and stability.
Manuel Reis Carneiro   +4 more
wiley   +1 more source

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