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.

Peer review evaluation tool

Abstract: A method for peer review evaluation of a product during a development stage comprises creating an evaluation header including selection of a moderator for a peer review team. The evaluation continues by identifying team members and distributing artifacts to complete the review evaluation header. An overview of the evaluation artifacts is conducted by the author, moderator and each of the team members. Following the overview each of the team members identifies potential defects in artifacts and records the potential defects in an action request database. A peer review meeting then evaluates each of the potential defects for either acceptance of a potential defect or rejection of the potential defect. The author of the evaluation team prepares a report of accepted defects and this report is entered into the action request database. The author and/or moderator monitors the action request database as a follow-up to determine if a rework has been made to the identified accepted defects. This is a continuing effort until the accepted defects have been corrected.

Detection Performance of the Cell Averaging LOG/CFAR Receiver

Abstract: The cell averaging LOG/CFAR receiver is a special implementation of a constant-false-alarm-rate (CFAR) receiver in which the noise level estimate is derived from a set of contiguous time samples of the output of a logarithmic (LOG) detector as obtained from a tapped delay line. This CFAR receiver is capable of operating over a larger dynamic range of noise levels than a conventional cell averaging CFAR receiver, but with somewhat poorer detectability. The performance in stationary Gaussian noise of the cell averaging LOG/CFAR receiver with no post-detection integration is determined in this paper. For a small number of reference noise samples, results were obtained by a Monte Carlo simulation using the technique of importance sampling. For a large number of reference noise samples, a second moment analysis gave the desired results. Both these results can be summarized in the following simple formula, NLOG = 1.65NLIN - 0.65, which relates the number of reference samples required by each of the two receivers for equivalent performance. Thus, for the cell averaging LOG/CFAR receiver to give the same detection performance as the conventional cell averaging CFAR receiver, the number of reference noise samples has to be increased by up to 65 percent.

Method and apparatus for global positioning system based cooperative location system

Abstract: A cooperative location system for use with a Global Positioning System ("GPS"). The system includes a beacon that receives GPS signals and transmits GPS data representing the location of the beacon to a remote locator. The locator receives the beacon's GPS data from the beacon. Based on the beacon's GPS data, a reference direction provided by a compass, and the locator's own GPS data, the locator calculates range and direction information to the beacon.

CMOS VLSI output driver with controlled rise and fall times

Abstract: A CMOS output driver having precise control of rise and fall times of signals generated from the output driver on a VLSI semiconductor chip. Two time-dependent voltage generators provide a separate ramp signal to each one of the gates of a CMOS inverter circuit. The ramp signal characteristics of each voltage generator are determined by the combination of a controlled current source charging a known capacitance.

DC and microwave models for Al x Ga 1-x As/GaAs high electron mobility transistors

Abstract: Models are developed for the dc I-V curves and microwave small-signal parameters of the Al x Ga 1-x As/GaAs heterojunction field-effect transistor, called the high electron mobility transistor (HEMT). An analytic velocity versus field model is used, along with the exact variation with density of the GaAs two-dimensional electron gas Fermi level. A numerical integration is used to obtain the drain voltage for a given gate voltage and source-drain current. The resulting I-V curves are in excellent agreement with the experimental data from four different groups. This model is also used to calculate the transconductance and gate capacitance, and a model is developed for the source resistance. These are used to calculate f_{\max} , the maximum frequency of oscillation, for a range of values of gate length, of AlGaAs alloy composition and doping, and of the thickness of the undoped A1GaAs spacer layer. The results are compared with measured data for HEMT's as well as for a similar GaAs FET with 0.35-µm gate length.