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Institution

Raytheon

CompanyWaltham, Massachusetts, United States
About: Raytheon is a company organization based out in Waltham, Massachusetts, United States. It is known for research contribution in the topics: Signal & Antenna (radio). The organization has 15290 authors who have published 18973 publications receiving 300052 citations.
Topics: Signal, Antenna (radio), Radar, Turbine, Amplifier


Papers
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Journal ArticleDOI
Michael N. Gardos1
TL;DR: In this article, a hypothesis correlating the oxygen stoichiometry of the Ti n O2n−1 Magneli phases of the rutile polymorph of titania with their tribological behavior was examined.
Abstract: In part I of this paper series, wide temperature range SEM-tribometric results generated in vacuum and various partial pressures of oxygen are combined with relevant literature data to examine a hypothesis correlating the oxygen stoichiometry of the Ti n O2n−1 Magneli phases of the rutile polymorph of titania with their tribological behavior. Single-crystal and polycrystalline rutile specimens of narrow stoichiometry ranges were sliding against α-SiC and themselves. The surface shear strength changes were determined as a function of the thermal–atmospheric test environment, and the shear strength values were estimated by the coefficients of friction, the real area of contact and the published yield strength of rutile. The data appear to be sufficient and sufficiently reliable to confirm the accuracy of the hypothesis. The tendency of the rutile stoichiometry (ergo the friction) to shift as a function of temperature and partial pressure of oxygen causes this material to be thermo-oxidatively unstable for tribological applications in extreme environments. In part II, a study is described to formulate oxidatively more stable Magneli phases by Cu-doping, and test the new materials by SEM tribometry using a procedure used for pure rutile here in part I. By employing this doping methodology similar to creating high-temperature superconductive oxides in part II, some feasibility of producing oxidatively stable, lubricious oxides with acceptably low wear rates is indicated.

88 citations

Journal ArticleDOI
J.C. Huang1, G. Jackson1, S. Shanfield1, A. Platzker1, P. Saledas1, C. Weichert1 
TL;DR: In this paper, a model based on surface states was proposed to explain this phenomenon, which then led to the use of charge-screen layers and a double-recessed gate process to suppress surface effects.
Abstract: The authors determined that RF drain current degradation is responsible for the poor power performance of wide-recessed pseudomorphic high-electron-mobility transistors (PHEMTs). A model based on surface states was proposed to explain this phenomenon, which then led to the use of charge-screen layers and a double-recessed gate process to suppress surface effects. Combined, these two modifications increased the device's gate-drain reverse breakdown voltage without causing a degradation in the transistor's RF drain current. This allowed the simultaneous achievement of high power-added efficiency and high power density which established a new performance record for power PHEMTs at X- and Ku-bands. Delay time analysis of single- and double-recessed PHEMTs revealed that the benefit of a larger breakdown voltage in the latter device design came at the cost of a larger drain delay time. Drain delay accounted for 45% of the total delay when the 0.35- mu m double-recessed PHEMT was biased at V/sub ds/=6 V. >

88 citations

10 Nov 1999
TL;DR: This position paper examines the individual tracking technologies available and concludes that for the near term, a hybrid solution is the only viable approach.
Abstract: Developing Augmented Reality systems that work outdoors, rather than indoors in constrained environments, will open new application areas and motivate the construction of new, more general tracking approaches. Accurate tracking outdoors is difficult because we have little control over the environment and fewer resources available compared to an indoor application. This position paper examines the individual tracking technologies available and concludes that for the near term, a hybrid solution is the only viable approach. The distortion measured from an electronic compass and tilt sensor is discussed.

88 citations

Journal ArticleDOI
TL;DR: An infrared imaging system that uses a three-by-three lenslet array and achieves Rayleigh criteria resolution comparable with a conventional single-lens system with an optical system length of 26 mm is described.
Abstract: The size of infrared camera systems can be reduced by collecting low-resolution images in parallel with multiple narrow-aperture lenses rather than collecting a single high-resolution image with one wide-aperture lens. We describe an infrared imaging system that uses a three-by-three lenslet array with an optical system length of 2.3 mm and achieves Rayleigh criteria resolution comparable with a conventional single-lens system with an optical system length of 26 mm. The high-resolution final image generated by this system is reconstructed from the low-resolution images gathered by each lenslet. This is accomplished using superresolution reconstruction algorithms based on linear and nonlinear interpolation algorithms. Two implementations of the ultrathin camera are demonstrated and their performances are compared with that of a conventional infrared camera.

88 citations

Proceedings ArticleDOI
14 Jun 1993
TL;DR: In this article, the authors state that a two-port system is stable if and only if K>1 and mod Delta /sup s/mod >, where K is the number of channels in the system.
Abstract: Many papers and textbooks and the leading CAD (computer-aided design) packages state that a two-port is stable if and only if K>1 and mod Delta /sup s/ mod >

88 citations


Authors

Showing all 15293 results

NameH-indexPapersCitations
Peter J. Kahrilas10958646064
Edward J. Wollack104732102070
Duong Nguyen9867447332
Miroslav Krstic9595542886
Steven L. Suib8986234189
Gabriel M. Rebeiz8780632443
Charles W. Engelbracht8321028137
Paul A. Grayburn7739726880
Eric J. Huang7220122172
Thomas F. Eck7215032965
David M. Margolis7022717314
David W. T. Griffith6528814232
Gerhard Klimeck6568518447
Nickolay A. Krotkov6321911250
Olaf Stüve6329014268
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
20232
20228
2021265
2020655
2019579
2018457