Results 121 to 130 of about 777 (161)
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Reflection characteristics of a retrodirective PARC
IGARSS 2003. 2003 IEEE International Geoscience and Remote Sensing Symposium. Proceedings (IEEE Cat. No.03CH37477), 2004Reflection characteristics of a retrodirective PARC (polarimetric active radar calibrator) were measured in a radio anechoic chamber. The reflection beamwidth was twice as wide as that of a conventional array reflector of the same size, and the measured RCS was 40.8 dBm/sup 2/ that almost agreed with the predicted value of 41.5 dBm/sup 2/.
Masaharu Fujita +2 more
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Use of an active retrodirective antenna array as a multipath sensor
, 1997 The use of an active retrodirective antenna as an indicator of multipath propagation effects is investigated by the authors. It is shown that the flat azimuthal gain response normally associated with a retrodirective antenna array can be significantly ...
V F Fusco
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Frequency stability in adaptive retrodirective arrays
IEEE Transactions on Aerospace and Electronic Systems, 2000The frequency stability of communications or remote sensing systems using phase conjugation as a means of retrodirective signaling is developed under the influence of constant rectilinear motion. The results indicate that for dynamic mobile platforms such as aircraft, helicopters, and ground vehicles the retrodirective properties of phase conjugating ...
Leo D. DiDomenico, Gabriel M. Rebeiz
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A Retrodirective Microwave Barcode
2019 IEEE MTT-S International Microwave Symposium (IMS), 2019A passive, long range, wide angle, chipless radio-frequency identification (RFID) tag operating in the S-band is presented in this paper. The proposed design consists of a broadband Van Atta retrodirective array incorporating perfectly matched bandstop filters in its feeding network, to encode identifying information across the frequency spectrum in ...
Kevin Xu +3 more
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Radacoustic detection of projectiles by a retrodirective radar
2010 IEEE Radar Conference, 2010An X-band retrodirective radar is shown experimentally to provide two signals from a firearm deployed at moderate range: (1) the normal reflection from the airborne projectile as it approaches the radar, and (2) a secondary reflection from the muzzle-blast acoustic wave.
Lu, Mingzhi +2 more
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Novel retrodirective beam formation techniques
27th European Microwave Conference, 1997, 1997This paper presents two novel active antenna architectures for retrodirective beam formation which rely on heterodyne phase techniques for their operation. Both the methods use the phase conjugate properties of a mixer driven with f0 and 2f0 signals for retrodirective beam formation. In the first approach frequency diversity, coupled with power divider
S.L. Karode, V.F. Fusco
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Spherical retrodirective array
IEEE Transactions on Antennas and Propagation, 1964This paper derives the characteristics of a spherically-shaped retrodirective space array. The array can receive an incoming signal over 4\pi steradians, amplify, frequency translate, and modulate this signal, and then return it in the direction of the incident wave.
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A retrodirective null-scanning array
2010 IEEE MTT-S International Microwave Symposium, 2010A full-duplex self-steering array using power detection and phase shifting is presented. The system utilizes two sub-arrays to autonomously steer its beam toward an interrogating signal. A two-element null-scanning array is used for power detection where the interrogator direction is determined by the location where minimum power is detected ...
R. T. Iwami +4 more
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Spatial Fading in Retrodirective Channels: An Experimental Study
IEEE Transactions on Wireless Communications, 2021Simple, low-power, reliable backscatter communication systems must overcome the severe, double-fading nature of the backscatter channel. In this article, we show experimentally that when a conventional transponder is replaced by a retrodirective transponder in backscatter systems, those deep fading nulls are reduced by as much as two orders-of ...
Mohammad Alhassoun, Gregory D. Durgin
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Experiments With Retrodirective Arrays
Optical Engineering, 1982A summary of experiments is presented which show how retrodirective arrays have been used to approximate phase conjugation.
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