Raytheon

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.

A mm-Wave Power-Harvesting RFID Tag in 90 nm CMOS

Abstract: A mm-wave power-harvesting RFID tag is implemented in 90 nm CMOS. Operation at mm-wave reduces antenna size and could allow antenna integration on-chip. This, together with power harvesting that can be used in lieu of a battery, can result in a pinless, CMOS-only tag with no package and no off-chip components whatsoever. The tag harvests energy from the incoming mm-wave continuous wave (CW) signal transmitted by the reader and then uses a 60 GHz free-running oscillator to transmit back pulse-width modulated bursts. An in-depth treatment of the voltage multiplier and associated matching network and implications on tag range are presented. With 2 dBm mm-wave input power, the tag achieves a rate of 5 kb/s. The RFIC size is 1.3 × 0.95 mm2 including pads.

Open road cashless toll collection system and method using transponders and cameras to track vehicles

Abstract: A cashless toll collection system and method that detects vehicles using transponders for prepaid customers and cameras for casual or non-transponder equipped vehicles. The system has a plurality of roadside toll collectors, one or more toll transaction processors, and a revenue management system. Each roadside toll collector has a vehicle to roadside communications system that communicates with transponders disposed in transponder equipped vehicles and generates entry and exit transaction reports indicating the entry and exit locations and times of the transponder equipped vehicles. Each roadside toll collector has a plurality of license plate cameras that selectively provide video images of license plates of vehicles that are not equipped with a transponder. Each roadside toll collector has a vehicle detector and classification system that detects the presence of vehicles, controls the cameras to capture the video images of the license plates, and generates entry and exit transaction reports indicating the entry and exit locations and times, and the license plate images of each detected vehicle that is not equipped with a transponder. The toll transaction processor processes the transaction reports to generate tolling transactions for each vehicle. The revenue management system processes the tolling transactions to generate tolls for each vehicle and generate bills for use of the toll road.

Self-organized coherence in fiber laser arrays

Abstract: Self-organized coherence between fiber lasers has been reported both via all-fiber 2x2 directional coupler trees and in spatially multi-core fibers. We have taken this a major step forward, coupling together a number of independent fiber lasers to obtain a spatially and spectrally coherent far field, with no active length, polarization, or amplitude control. The near field output comes from a spatial array rather than from a single fiber, making this approach scalable to extremely high power.

Observations of the Earth's topography from the Shuttle Laser Altimeter (SLA): Laser-pulse Echo-recovery measurements of terrestrial surfaces

Abstract: Meter-precision topographic measurements of a diverse suite of terrestrial surfaces have been accomplished from Earth orbit using the Shuttle Laser Altimeter (SLA) instrument flown aboard the Space Shuttle Endeavour in January of 1996. Over three million laser pulses were directed at the Earth by the SLA system during its ∼ 80 hours of nadir-pointing operation at an orbital altitude of 305 km (+/- 10 km). Approximately 90% of these pulses resulted in valid range measurements to ocean, land, and cloud features. Of those which were fired at land targets, 57% resulted in valid surface ranges, the remainder being cloud tops, false alarms, or missed shots. The SLA incorporated an electronic echo-recovery system into a pulsed, time-of-flight laser altimeter instrument in order to capture and characterize the vertical structure within each 100 m diameter surface footprint. The echoes recorded by SLA demonstrate aspects of the vertical structure of the nearly ubiquitous vegetation cover on the planet, as well as sensitivity to local slopes, surface reflectivity, and vertical ruggedness. With a vertical resolution of 0.75 m and horizontal sampling at 0.7 km length scales, SLA provides a new form of high vertical accuracy topographic data for studying problems related to the dynamics of the Earth's surface. Assessment of the error budget associated with the SLA experiment suggests that ∼2.8 m (RMS) precision was achieved for ranging measurements to oceanic surfaces, for which there are over 700,000 examples. With the availability of a precision radial orbit and post-flight Shuttleattitude information, a mid-latitude (+ 28.5° to −28.5°), georeferenced database of topographic ground control point elevations has been achieved using SLA data, consisting of ∼ 344,000 land measurements. Each of these measurements is geolocated to within 1–2 SLA footprints (100–200 m) on the Earth's surface, with vertical errors that approach the limits of resolution (0.75 m) of the instrument in topographically benign regions. When compared to available Digital Elevation Models (DEM's) with stated vertical accuracies on the order of 10–16 m, SLA's measurements differ by no more than 11 m to 46 m RMS in rugged terrain. We have computed a total vertical roughness parameter for all multi-peaked SLA echoes using a multi-Gaussian decomposition technique and have observed a very high degree of correlation of this parameter with global landcover classes. In some cases (∼6%), SLA echoes clearly resolve both the ground surface and vegetation canopy within a single footprint, suggesting that the modal height of equatorial vegetation is ∼ 18 m. The global distribution of total vertical roughness varies from ∼ 5 m to 60 m, with a mean value of 27 m and a standard deviation of 12 m. SLA successfully served as a pathfinder for high vertical resolution orbital topographic remote sensing instrumentation, and demonstrated the first high resolution echo-recovery laser altimeter observations over land surfaces.