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.

2-20-GHz GaAs Traveling-Wave Power Amplifier

Abstract: Power amplification in FET traveling-wave amplifiers is examined, and the mechanisms which limit power capability of the amplifier are identified. Design considerations for power amplification are discussed. A novel single-stage and two-stage monolithic GaAs traveling-wave power amplifier with over 250-mW power output in the 2-20-GHz frequency range is described.

Doppler spread measurements of indoor radio channel

Abstract: The temporal variations caused by human movement or human-induced motion of the communication equipment, on the otherwise static indoor radio channel, are measured. For the reported narrowband measurements, a maximum Doppler spread of 6.1 Hz and a maximum RMS Doppler bandwidth of 0.87 Hz are observed.

Amorphous Silicon Microbolometer Technology

Abstract: Highly sensitive hydrogenated amorphous silicon (a-Si:H) microbolometer arrays have been developed that take advantage of the high temperature coefficient of resistance (TCR) of aSi:H and its relatively high optical absorption coefficient. TCR is an important design parameter and depends on material properties such as doping concentration. Ultra-thin (∼2000 A) aSiNx:H/a-Si:H/ a-SiNx:H membranes with low thermal mass suspended over silicon readout integrated circuits are built using RF plasma enhanced chemical vapor deposition (PECVD) and surface micromachining techniques. The IR absorptance of the bolometer detectors is enhanced by using quarter-wave resonant cavity structures and thin-film metal absorber layers. To ensure high thermal isolation the microbolometer arrays are vacuum packaged using wafer level vacuum packaging. Imaging applications include a 120×160 a-Si:H bolometer pixel array IR camera operating at ambient temperature. Non-imaging applications are multi-channel detectors for gas sensing systems.

Personal messaging system and method

Abstract: A pager device received paging messages. The user reads a paging message, selects one of a set of stored, predetermine reply messages, and transmits the selected reply message from the pager. The reply signal is received by one of a set of local cellular receivers, which sends the received signal to a computer for interpretation. The computer initiates an action based on interpretation of the received reply signal. The communication system communicates with large numbers of pagers in a time and energy efficient manner. The pagers are associated with items located in a communication region that is interrogated by an interrogator on a one-to-many basis using broadcast commands, on a one-to-one basis using directed commands or on a combination basis using both methods. Messaging occurs through organized transmission and reception of signals between the pagers and the interrogator. A batch collection protocol uses a combined one-to-many and one-to-one communication system that effectively resolves communication contentions. The batch collection protocol employs a plurality of collection periods which communicate with large or unknown numbers of portable pagers.

IMM/MHT solution to radar benchmark tracking problem

Abstract: The benchmark problem addresses the efficient allocation of an agile beam radar in the presence of highly maneuverable targets and radar electronic countermeasures (ECM). This paper presents methods for applying an interacting multiple model/multiple hypothesis tracking (IMM/MHT) tracker to this radar tracking and resource allocation problem. The manner in which IMM/MHT tracking and data association methods lead to efficient agile beam radar allocation is discussed and results showing that this approach is more efficient than previously proposed methods is presented. However, results indicate that the presence of ECM requires that the allocated signal-to-noise ratio (SNR) be increased and the allowable track position uncertainty be decreased from the values that would be chosen to minimize energy allocation when no ECM is present.