Results 31 to 40 of about 360,981 (266)
IEEE Access, 2023 This work is concerned with a detailed study of an active antenna, which can serve as a prototype of a phased array antenna element for a future lunar very-low-frequency (VLF) radio telescope operating in the frequency range of 1–30 MHz.
Peter L. Tokarsky +2 more
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The Radiation Pattern on an Ultrasonic Focusing Radiator [PDF]
The Journal of the Acoustical Society of America, 1947 A focusing quartz radiator made in the form of a concave-convex lens of constant thickness (and being X-cut on the axis) should radiate spherical sound waves which focus at the center of curvature of the radiator surfaces. Because of wave diffraction, the focus should deviate from infinitely sharp in the same manner as is well known in the optical ...
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Field Tests for Generating Source System and Picking the Seismic Shear Waves to Meet the Engineering Purposes Requirements. [PDF]
Kirkuk Journal of Science, 2019 Many seismic field tests were carried for the designed and modified seismic apparatuses using to generate seismic shear waves. These apparatus includes: "wooden plank" horizontal traction shear wave source, and a modified geophone for picking the SH-Wave
Muhana Ahmed
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Embedding Information in Radiation Pattern Fluctuations [PDF]
2020 IEEE International Symposium on Information Theory (ISIT), 2020 The radiation pattern of transmit antennas varies and fluctuates as receivers change their location, other objects move around, and due to the antenna design itself. In this paper, we demonstrate how this observation can be exploited to align most of the interference signal power and significantly increase the average achievable communication rates ...
Milad Johnny, Alireza Vahid
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Brain and SpineIntroduction: Cervical central spinal stenosis (CCSS) is a leading cause of adult spinal cord dysfunction. Magnetic resonance imaging (MRI) is the reference standard, but reporting is time-consuming and subject to inter-observer variability.
Vasileios Mougios +8 more
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Plant Foliar Geometry as a Biomimetic Template for Antenna Design
Biomimetics, 2023 Plant diversity includes over 300,000 species, and leaf structure is one of the main targets of selection, being highly variable in shape and size. On the other hand, the optimization of antenna design has no unique solution to satisfy the current range ...
Jose Ignacio Lozano +5 more
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Calculation of radiation patterns
Electronics Letters, 1969 The letter proves that two distinct methods of calculating the radiation pattern of a spherical-aperture distribution are mathematically equivalent, i.e. by a spherical-harmonic expansion or by Silver's far-field formula. The merits of each method and their extension to arbitrary-shaped apertures are briefly discussed.
J.R. James, L.W. Longdon
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Физика волновых процессов и радиотехнические системыBackground. Antenna arrays are widely used in a variety of modern radio engineering systems for wireless communication and radar. The phenomenon of mutual coupling of antenna elements, which is manifested in practical implementation, may cause noticeable
Anatoly M. Bobreshov +4 more
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Microstrip Patch Antenna for GNSS Applications
Applied SciencesThis research paper presents the results of an analysis conducted on a microstrip patch antenna designed to operate within the 1.559–1.591 GHz frequency band, which encompasses three major satellite constellations: GPS, Galileo and BeiDou.
Hatice-Andreea Topal +1 more
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Физика волновых процессов и радиотехнические системы, 2019 The apertures amplitude-phase distribution of a linear antenna array, ensuring the formation of frequency-independent direction-finding characteristics in a wide frequency band, is considered.
N.I. Bobkov +2 more
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