Results 81 to 90 of about 55,869 (299)

Broadband Fizeau Interferometers for Astrophysics [PDF]

open access: yes, 2010
Measurements of the 2.7 K cosmic microwave background (CMB) radiation now provide the most stringent constraints on cosmological models. The power spectra of the temperature anisotropies and the $E$-mode polarization of the CMB are explained well by the ...
Malu, Siddharth Savyasachi   +1 more
core  

Cool Kitchen: Processing Starch and Eggshell Powder into Sustainable Coatings for Passive Daytime Cooling

open access: yesAdvanced Functional Materials, EarlyView.
A food‐grade cooling composite made from starch and recycled eggshell powder offers a scalable, ultra‐low‐cost solution for passive daytime radiative cooling. Easily prepared using basic kitchen tools, this material empowers communities, even in areas with limited infrastructure, to stay cooler during worsening summer heat waves.
Qimeng Song   +3 more
wiley   +1 more source

Azimuth Null-Reduced Radiation Pattern, Ultralow Profile, Dual-Wideband and Low Passive Intermodulation Ceiling Mount Antenna for Long Term Evolution Application

open access: yesIEEE Access, 2019
An ultralow profile, dual-wideband and low passive intermodulation (PIM) in-building ceilingmount antenna for long term evolution (LTE) distributed antenna system (DAS) application is presented.
Kok Jiunn Ng   +4 more
doaj   +1 more source

Broadband microstrip patch antenna

open access: yesElectronics Letters, 1998
The characteristics of a rectangular microstrip antenna with an L-shaped probe are investigated. A foam layer with a thickness of around 10% of the wavelength is used as the supporting substrate. An impedance bandwidth of 35% and an average gain of 7.5 dBi can be achieved. The radiation pattern is stable across the passband.
K.M. Luk, C.L. Mak, Y.L. Chow, K.F. Lee
openaire   +1 more source

MOFs and COFs in Electronics: Bridging the Gap between Intrinsic Properties and Measured Performance

open access: yesAdvanced Functional Materials, EarlyView.
Metal‐organic frameworks (MOFs) and covalent organic frameworks (COFs) hold promise for advanced electronics. However, discrepancies in reported electrical conductivities highlight the importance of measurement methodologies. This review explores intrinsic charge transport mechanisms and extrinsic factors influencing performance, and critically ...
Jonas F. Pöhls, R. Thomas Weitz
wiley   +1 more source

Electrically Tunable On‐Chip Topological Photonics with Integrated Carbon Nanotubes

open access: yesAdvanced Functional Materials, EarlyView.
This work demonstrates electrically tunable on‐chip topological THz devices by integrating 2D carbon nanotube (CNT) sheets with valley‐Hall photonic crystals, enabling broadband transmission modulation (71% modulation depth) and tunable narrowband filtering (0.54 GHz shift) through electrically induced thermal tuning. This advancement paves the way for
Jifan Yin   +7 more
wiley   +1 more source

Multiband Switchable Microwave Absorbing Metamaterials Based on Reconfigurable Kirigami–Origami

open access: yesAdvanced Functional Materials, EarlyView.
A reconfigurable metamaterial featuring tunable microwave‐absorbing and load‐bearing performance is proposed. Stretchable kirigami and bistable origami configurations are integrated as actuating components, and the synergistic deformation mechanisms are systematically analyzed.
Weimin Ding   +7 more
wiley   +1 more source

Design of a Highly Durable X-Band Array Antenna for Military Radar Systems [PDF]

open access: yesJournal of Electromagnetic Engineering and Science
In this paper, we propose a design technique for a highly durable X-band array antenna operating in the harsh maritime environment of military ships.
En-yeal Yim, Doyoung Jang, Hosung Choo
doaj   +1 more source

A Broadband Bow-Tie Cavity-Backed Slot for Traveling-Wave Arrays in the Millimeter-Wave Band [PDF]

open access: yes, 2019
The use of bow-tie geometries to enhance the characteristics of a radiating element previously proposed by the authors is presented. The previous element consisted of a broadband cavity-backed slot in transmission configuration. The bow-tie shape of the
Abdo Sánchez, Elena   +2 more
core  

Photonic Engineering Enables All‐Passive Upconversion Imaging with Low‐Intensity Near‐Infrared Light

open access: yesAdvanced Functional Materials, EarlyView.
A passive upconversion imaging system enables the observation of scenes illuminated by low‐intensity incoherent near‐infrared light from 750 to 930 nm, by converting it into the visible without the use of external power. The upconverter is enabled by triplet–triplet annihilation in a bulk heterojunction, with absorption enhanced by plasmonic resonators
Rabeeya Hamid   +13 more
wiley   +1 more source

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