NASA 1998 SBIR Phase I


PROPOSAL NUMBER: 98-1 13.09-4994

PROJECT TITLE: GaAs Planar Varactor Multipliers for Radiometer Applications

TECHNICAL ABSTRACT (LIMIT 200 WORDS)

We propose to design frequency multipliers with output frequencies at 118 GHz, 183 GHz, and 380 GHz. Highly sensitive radiometers operating in the millimeter-wave and submillimeter-wave regime require low noise local oscillators (LO). An ideal LO source exhibits low noise, high output power and efficiency, large bandwidth, high tolerance to mechanical and thermal stress, low mass, and low cost. The source would also ideally be compact and reliable. Most successful frequency multipliers have been either narrow band or highly inefficient and most multipliers employ various mechanical tuners that must be carefully adjusted to optimize the multiplier performance at a given frequency.Virginia Millimeter Wave is uniquely qualified to design and build frequency multipliers that are tuner-less and yet exhibit all of the desirable qualities listed earlier. Our multipliers are based on the earlier work of Dr. David Porterfield, the principal investigator for this proposal. Dr. Porterfield has developed a proven 40/80 GHz frequency doubler that exhibits 50% efficiency at an output power of 100 mW, and a 17% fixed-tuned bandwidth. He has also developed an 80/160 GHz multiplier with a 15% fixed-tuned bandwidth and greater than 2 mW output power over the entire 144-180 GHz band.

POTENTIAL COMMERCIAL APPLICATIONS

Millimeter-wave and submillimeter-wave sources are used primarily as local oscillators in heterodyne radiometers for remote sensing, atmospheric physics, and radio astronomy. They also find application in spectroscopy, imaging, compact radar, collision avoidance radar, and a wide range of laboratory bench functions. Although there are many atmospheric absorption bands above 50 GHz, there are also a large number of low-loss "windows" in this regime that may ultimately become important for the telecommunications industry. The absorption bands may also be useful for telecommunications in the specific areas of wireless local area networks (LAN) and short-range secure links.

NAME AND ADDRESS OF PRINCIPAL INVESTIGATOR

David Porterfield
Virginia Millimeter Wave
706 Forest St., Suite D
Charlottesville , VA 22903

NAME AND ADDRESS OF OFFEROR

Virginia Millimeter Wave
706 Forest St., Suite D
Charlottesville , VA 22903