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Ward, J.

Publications and source records attributed to Ward, J..

14 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2006

THz multiplier circuits

Planar Schottky diode technology has been utilized to fabricate high-power broad-band monolithic multiplier circuits that can produce appreciable power well into the THz range. The chip fabrication technology that has been developed allows for robust circuit designs that can be easily packaged in conventional waveguide blocks. An overview of the capability of GaAs based Schottky diode multipliers will be presented.

Maestrini, A.↗
NASA NTRS2003

1400-1900 GHz local oscillators for the Herschel Space Observatory

JPL continues to develop robust planar, all solid-state sources to cover the 1414 to 1908 GHz band. These sources will be used as local oscillators to drive hot electron bolometer (HEB) heterodyne mixers on the Herschel Space Observatory to observe high resolution spectra in the interstellar medium. We report our current progress and present recent results.

Schottky diode frequency multiplier THz local osci↗
NASA NTRS2002

THz frequency receiver instrumentation for Herschel's Heterodyne Instrument for Far Infrared (HIFI)

The Heterodyne Instrument for Far Infrared (HIFI) on ESA's Herschel Space Observatory is comprised of five SIS receiver channels covering 480-1250 GHz and two HEB receiver channels covering 1410-1910 GHz. The NASA developed components represent a significant advancement in the available performance. The current state of the art for each of these devices is presented along with a programmatic view of the development effort.

heterodyne↗
NASA NTRS1993

ROWS wave spectral data collected in SAXON-FPN, November 1990

High-resolution directional wave spectra obtained with the NASA Ku-band radar ocean wave spectrometer (ROWS) on the Naval Research Laboratory P-3 aircraft during SAXON-FPN (SAR and X-Band Ocean Nonlinearities Experiment-Forschungsplattform Nordsee) experiments in the North Sea in November 1990 are presented. This experiment was the first in which the ROWS was operated with its new pc-based high-speed digital data acquisition system.

Jackson, F.↗
NASA NTRS1984

An updated history of NACA/NASA rotary-wing aircraft research 1915-1984

Highlights are drawn from 'A History of NACA/NASA Rotating-Wing Aircraft Research, 1915-1970' by F. Gustafson to build an historical base upon which to build an extension from 1970-1984. Fundamental changes in how NASA conducted rotary-wing research in the early 1970s included an increasing level of contract research and closer ties with research conducted by the U.S. Army. The work done at the Army Research Laboratories at Ames, Langley, and Lewis Research Centers during 1970-1976 is briefly reviewed. In 1976 the Ames Research Center was assigned the Lead Center responsibility for helicopter research, though Langley retained research roles in structures, noise, dynamics, and aeroelasticity in support of rotorcraft. By 1984, NASA Rotorcraft Program Funding reached $35 million per year.

Ward, J.↗
NASA NTRS1974

Correlation effects in the theory of combined Doppler and pressure broadening. I - Classical theory

An investigation is conducted of the combined effects of radiator-perturber collisions and radiator translational motion in the context of foreign gas broadening of optical transitions in neutral radiators. Questions concerning the speed-dependent collision frequency are considered and aspects of general theory are explored, taking into account the correlation function, the ensemble average, and the kinetic equation formalism. An elementary solution is discussed along with a one-perturber approximation, inverse power law model calculations, and a comparison with the Voigt profile.

Ward, J.↗