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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 991 records · Page 55
All sourcesNASA NTRSDOE OSTI
NASA NTRS2013

GRC RF Propagation Studies

NASA Glenn Research Center has been involved in the characterization of atmospheric effects on space communications links operating at Ka-band and above for the past 20 years. This presentation reports out on the most recent activities of propagation characterization that NASA is currently involved in.

nasa networks↗
NASA NTRS2017

Multi-Layer RF Tissue Phantoms for Mimicking a Human Core

This work presents the design recipe, fabrication process and characterization of tissue-simulating materials, configured as a physical model to mimic the electrical and some physical properties of an abdominal cavity. The complete three-layer design is called the human core model (HCM) see Fig. 1. To our knowledge, presented is the first hybrid skin-muscle phantom developed to mimic the electrical properties of the intervening tissue layers of an abdominal cavity within the frequency band of 1 GHz - 2 GHz, a band of interest for human body sensing due to its deep detection depth.

Biomedical Microwave Sensing↗
NASA NTRS2001

Advanced RF front end technology

The ability to achieve low-mass low-cost micro/nano-spacecraft for deep space exploration requires extensive miniaturization of all subsystems.

Advanced↗
NASA NTRS1994

(abstract) Design and Testing of a Fullerene RF Ion Engine

Because of the large mass, low ionization potential and large electron impact ionization cross section, use of buckminsterfullerene (C 60 ) as a propellant might result in significant increases in ion engine efficiency over that obtained with xenon at low specific impulse. Consequently, an experimantal program to investigate the feasibility of using fullerenes as a propellant was initiated. To eliminate the possibility of hot cathode surfaces causing fragmentation, fabrication of a radio-frequency discharge chamber was pursued. Experimental results using the radio-frequency source will be presented.

fullerenes↗
NASA NTRSDate not supplied

Metal Contact Processing Experiments Towards Realizing 500 °C Durable RF 4H-SiC BJTs

This paper presents results from metal contact processing experiments towards the implementationof durable 500 deg.C high-frequency 4H-SiC bipolar junction transistors (BJTs). Specifically, p-type ohmic contacts have been demonstrated on a 0.25 μm-thick p-type homoepitaxial layer of doping 8 x 1018± 4 x 1018cm-3. Finally, preliminary current-voltage characteristics of fabricated BJTs are presented.

RF SiC↗
NASA NTRS2023

Metal Contact Processing Experiments Towards Realizing 500 °C Durable RF 4H-SiC BJTs

This paper presents results from metal contact processing experiments towards the implementation of durable 500 °C high-frequency 4H-SiC bipolar junction transistors (BJTs) . Specifically, p -type ohmic contacts have been demonstrated on a 0.25 μm-thick p -type homoepitaxial layer of doping 8 x 10 18 ± 4 x 10 18 cm -3 . Preliminary current-voltage characteristics of fabricated BJTs are presented.

4H-SiC BJT↗