NASA SBIR 2005 Solicitation


SUBTOPIC TITLE:Passive Microwave
PROPOSAL TITLE:High Reliability Oscillators for Terahertz Systems

SMALL BUSINESS CONCERN (Firm Name, Mail Address, City/State/Zip, Phone)
Virginia Diodes, Inc.
979 Second Street SE, Suite 309
Charlottesville, VA 22902-6172
(434) 297-3257

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
David W. Porterfield
979 Second Street SE, Suite 309
Charlottesville, VA  22902-6172
(434) 297-3257

TECHNICAL ABSTRACT (Limit 2000 characters, approximately 200 words)
To develop reliable THz sources with high power and high DC-RF efficiency, Virginia Diodes, Inc. will develop a thorough understanding of the complex interactions that occur within a chain of nonlinear frequency multipliers. These nonlinear interactions can cause rapid variations in power as the frequency or input power are tuned, including nulls and power surges that can damage individual components. Today, these problems are mitigated in three ways; i) mechanical tuning or bias adjustments, ii) laborious tweaking of each component in the chain until acceptable system performance is achieved, or iii) reduction of the system bandwidth and/or power specifications to avoid the most dramatic effects. However, each of these "solutions" either fundamentally limits the electrical performance of the terahertz source or dramatically reduces the ease-of-use of the system. This proposed effort represents the first systematic study of the complex interactions between cascaded nonlinear multiplier stages, with the goal of developing new multiplier and system designs that will reduce these unwanted effects. The resulting terahertz sources will achieve greater reliability, efficiency, bandwidth, and ease-of-use. In addition the new design rules will greatly reduce system design cycles and enhance manufacturability, thereby reducing costs. The knowledge gained through this research will be used to achieve vastly improved terahertz sources for NASA's atmospheric and radio astronomy missions; as well as a wide range of emerging commercial applications such as imaging systems for security screening and industrial process control.

POTENTIAL NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
This research will enable the development of more reliable, powerful and frequency agile terahertz sources for use as local oscillators for terahertz heterodyne receivers. The terahertz frequency band has been described as the most scientifically rich, yet unexplored region of the electromagnetic spectrum; primarily because of the wealth of molecular resonance lines that occur between 100 GHz and 10 THz. These resonances allow scientists to study the chemistry and dynamics of the Earth's atmosphere, molecular clouds in star forming regions and the atmospheres of other planets. NASA leads the world in the use of terahertz technology for the study of atmospheric chemistry and astrophysics from aircraft, balloons and spacecraft. As a specific and important example, according to Dr. Eric Jensen of the NASA Ames "Clouds are the largest source of uncertainty in computerized global climate models" and the terahertz frequency band is optimal for studying the effect of clouds on the energy balance in the atmosphere. Several planned and proposed missions will benefit from this research, including the SIRICE instrument to study Earth's atmosphere, atmospheric probes for Venus and Mars, and future radio astronomy missions that will inevitably follow the launch of Herschel. The Phase 2 research will result in the delivery of five highly integrated and reliable multiplier chains that will be useful for local oscillator system development and as breadboard prototypes for the SIRICE mission.

POTENTIAL NON-NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
Once a suitable technology base is established the terahertz frequency range will be as useful for scientific, military and commercial applications as the microwave and infrared bands are today. Scientific applications of terahertz technology include chemical spectroscopy, radio astronomy, plasma diagnostics, biomaterial analysis, electron spin resonance, and diagnostic instruments for particle accelerators. Terahertz applications related to national defense include compact range radars, covert communications systems, imaging systems, and chemical, explosive and bioagent scanners. Biomedical researchers envision the use of terahertz imaging and spectroscopy for the real time analysis of skin diseases such as skin cancer and rapid chemical analysis of patient's breath and other biological gases. Potential large-scale commercial applications include portal security imagers and scanners, medical diagnostics for clinical use, last-mile data links, and industrial process control.

NASA's technology taxonomy has been developed by the SBIR-STTR program to disseminate awareness of proposed and awarded R/R&D in the agency. It is a listing of over 100 technologies, sorted into broad categories, of interest to NASA.


Form Printed on 07-25-06 17:04