Results 11 to 20 of about 672,646 (267)

A Tunable K-Band Reflector

open access: yesIEEE Antennas and Wireless Propagation Letters, 2022
This letter presents a concept for a surface exhibiting tunable reflectivity that operates within the K-band using varactor diodes. Thereby, the impedance of a two-layer metasurface is controlled through lumped components at its back side and not from the front, where discrete elements would scatter the incident wave. A reflector's design, verification,
Christoph Kohlberger   +2 more
openaire   +1 more source

Special issue in honour of Prof. Reto J. Strasser - Revisiting JIP-test: An educative review on concepts, assumptions, approximations, definitions and terminology

open access: yesPhotosynthetica, 2020
The aim of this educative review is, by revisiting the JIP-test as introduced and further elaborated and extended by Professor Reto J. Strasser and his research group, to clarify concepts, assumptions, and approximations on which it is based, as well as ...
M. TSIMILLI-MICHAEL
doaj   +1 more source

Band K Satellite Receiver Signal and Radio Locator

open access: yesScientific Journal of Gdynia Maritime University, 2022
The last dozen or so years has seen significant and dynamic development in satellite technologies. Devices using satellites circulating in space for the purposes of general communication have ceased to be the domain of a narrow group of recipients ...
Marian Wnuk
doaj   +1 more source

Combined Single-Layer K-Band Transmitarray and Beamforming S-Band Antenna Array for Satcom

open access: yesIEEE Open Journal of Antennas and Propagation, 2022
In this paper, a dual-band antenna at 4.5 GHz and 25 GHz is presented. The antenna is a low-frequency phased patch antenna array combined with a high-frequency transmitarray with a fixed beam.
Daniel Edelgaard Serup   +2 more
doaj   +1 more source

K-Band Microlensing of the Inner Galaxy [PDF]

open access: yesThe Astrophysical Journal, 1995
10 pages, texfile requires phyzzx, no figures, send to gould@payne.mps.ohio-state.edu for postscript ...
openaire   +2 more sources

Hybrid‐fed shared aperture antenna array for X/K‐band airborne synthetic aperture radar applications

open access: yesIET Microwaves, Antennas & Propagation, 2021
The design of X/K‐band shared aperture antenna (SAA) single‐linear polarized K‐band, dual‐polarized (linear/circular) X‐band 36‐elements (6×6) planar array antenna with high gain, and low cost for airborne synthetic aperture radar systems is presented ...
Venkata Kishore Kothapudi, Vijay Kumar
doaj   +1 more source

The Hawaii K-band galaxy survey. 1: Deep K-band imaging

open access: yesThe Astrophysical Journal, 1994
We present the results of a very deep K-band survey with a 5 sigma total galaxy magnitude limit of K = 21.9 in the deepest field. A 5 sigma K-band-selected sample of 123 galaxies is presented, together with their optical colors. Only three galaxies in this sample are not detected at the 1 sigma level in Kron-Cousins I band.
L. L. Cowie   +5 more
openaire   +1 more source

Photochemical activity in Dalbergia nigra (Vell.) Fr. Allem. seedlings submitted to water deficit

open access: yesJournal of Forest Science, 2018
In this study, we evaluated the influence of the daily variation of both intensity of photosynthetically active radiation (PAR) and temperature on chlorophyll a fluorescence parameters in Jacarandá-da-Bahia seedlings submitted to two treatments: T1 ...
Natiele SANDRINI CELOVANE   +6 more
doaj   +1 more source

Wideband compact antennafor K-band applications [PDF]

open access: yesElectronics Letters, 2000
A compact coupled microwave active antenna is presented. This antenna is proximity fed, and consists of a square radiating element array on a polymer dielectric layer. The compactness of the antenna is obtained through technological optical processes and the parasitic patch phenomenon which increases the bandwidth.
Grzeskowiak, Marjorie   +2 more
openaire   +3 more sources

High-efficiency lithium niobate modulator for K band operation

open access: yesAPL Photonics, 2020
This paper reports a hybrid silicon nitride–lithium niobate electro-optic Mach–Zehnder-interferometer modulator that demonstrates overall improvements in terms of half-wave voltage, optical insertion loss, extinction ratio, and operational bandwidth. The
Abu Naim R. Ahmed   +5 more
doaj   +1 more source

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