Results 311 to 320 of about 189,054 (358)

Compound Scanning with a Phased Array

Ultrasonic Imaging, 1982
Compound scans made with a dynamically focussed phased array system have been produced in real time. The scanner, intended for abdominal imaging, has a large field of view. The compounding improves the acquisition of echoes from specular targets by changing the orientation of the insonifying beam and also reduces the speckle noise in grey scale images.
D P, Shattuck, O T, von Ramm
openaire   +2 more sources

Modeling of phased array transducers

The Journal of the Acoustical Society of America, 2005
Phased array transducers are multi-element transducers, where different elements are activated with different time delays. The advantage of these transducers is that no mechanical movement of the transducer is needed to scan an object. Focusing and beam steering is obtained simply by adjusting the time delay.
Rais, Ahmad, Tribikram, Kundu, Dominique, Placko   +2 more
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Optical phased-array ladar

Applied Optics, 2014
We demonstrate a ladar with 0.5 m class range resolution obtained by integrating a continuous-wave optical phased-array transmitter with a Geiger-mode avalanche photodiode receiver array. In contrast with conventional ladar systems, an array of continuous-wave sources is used to effectively pulse illuminate a target by electro-optically steering far ...
Juan, Montoya, Antonio, Sanchez-Rubio, Robert, Hatch, Harold, Payson   +3 more
openaire   +2 more sources

Optical phased array technology

Proceedings of the IEEE, 1996
Optical phased arrays represent an enabling new technology that makes possible simple affordable, lightweight, optical sensors offering very precise stabilization, random-access pointing programmable multiple simultaneous beams, a dynamic focus/defocus capability, and moderate to excellent optical power handling capability.
Paul F. McManamon, Terry A. Dorschner, David L. Corkum, Larry J. Friedman, Douglas S. Hobbs, Michael Holz, Sergey Liberman, Huy Q. Nguyen, Daniel P. Resler, Richard C. Sharp, Edward A. Watson   +10 more
openaire   +1 more source

Optimal Phase-Matching Strategy for Beam Scanning of Sub-Arrayed Phased Arrays

IEEE Transactions on Antennas and Propagation, 2019
The design of phased array antennas generating two functional beams is addressed here. The first/primary beam is fixed and it is generated at the element level (EL) through the complex (amplitude and phase) weighting coefficients, while the second/secondary one is synthesized at the subarray level by aggregating the array elements into nonoverlapped ...
Rocca, P., Hannan, M. H., Poli, L., Anselmi, N., Massa, A.   +4 more
openaire   +4 more sources

Phased arrays with sub-array architecture

Proceedings 2000 IEEE International Conference on Phased Array Systems and Technology (Cat. No.00TH8510), 2002
This paper presents a simplified true time delay beam steering at the element level which is no more complex than using a phase shifter at each element of the sub-array. The architecture described here makes multiple use of switched time-delays and thereby significantly reduces the complexity.
J.B.L. Rao, T.C. Cheston, J.Y. Choe, M.G. Parent, P.K. Hughes   +4 more
openaire   +1 more source

Wideband planar phased arrays for the square kilometre array

2010 IEEE International Symposium on Phased Array Systems and Technology, 2010
The Square Kilometre Array development demands a radio telescope with a high sensitivity, dual polarization and wide field of view over a broad bandwidth to meet the scientific goals. For the mid-frequencies of the SKA (nominally 400MHz to 1.4GHz) observation is preferred using wideband phased array to reduce the survey time over the sky.
Brown, A. K., Zhang, Y., Kant, D., De Vaate, J. G Bij   +3 more
openaire   +2 more sources

Protein Arrays III: Reverse-Phase Protein Arrays

2017
The reverse-phase protein array (RPPA) is to use highly specific antibodies to interrogate pan or posttranslationally modified protein targets, such as phosphorylated proteins, particularly the proteins involved in cell signaling pathways. In this protocol we will cover the preparation of cell (or tissue) lysates, sample printing, antibody validation ...
Yulin, Yuan, Xia, Hong, Zuan-Tao, Lin, Hongting, Wang, Mikala, Heon, Tianfu, Wu   +5 more
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RF Phase Shifters for Phased Arrays

2011
Phase shifters are essential components in a phased array for adjusting the phase of each antenna path and steering the beam. There are various types of conventional RF phase shifters, and they are analyzed in detail in this chapter.
Yu, Yikun, Baltus, Peter G.M., van Roermund, Arthur H.M.   +2 more
openaire   +1 more source

Selection of phased array configuration

1974 Antennas and Propagation Society International Symposium, 1974
A major decision in the design of phased array antennas is the selection of array configuration. Once the coverage sector, net antenna gain, effective radiated power (ERP) and other system requirements are established, the effects of (1) subdividing the coverage sector, i. e.
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