SBIR-STTR Award

A new generation of Ka-band helical traveling wave tube (TWT) power amplifiers with efficiencies of over 60% will be developed. The dramatic increase in efficiency over current state-of-the-art amplifiers with about 45% efficiency will be achieved by the introduction of a novel taper to suppress all parasitic power flow, the elimination of severs, and new approaches for the minimization of circuit losses. These innovations will lead to large reductions in power requirements, circuit size, and system weight, and will result in enormous cost savings for launch and operation of communication satellites. The proposed technology development promises to provide the biggest contribution to efficiency enhancement in helical TWTs since the introduction of velocity tapers some 35 years ago and will enable high frequency digital broadband communications for near-Earth and deep-space missions with multi-gigabit-per-second data rates.

Potential Commercial Applications:
Helical traveling wave tubes are the power amplifiers of choice in satellites for telecommunications, data transmission, broadcasting, and radar mapping. High frequency, high data rate digital communications and high power broadband electronic countermeasures are the primary space applications for our new technology. Additional high volume applications are in satellite ground stations, phased array antennas, microwave power modules, radar for air traffic control and weather forecasting, and medical as well as scientific areas. The successful development of a new generation of helical TWTs with very high efficiencies will significantly increase the global competitiveness of the U.S. power tube industry.

This project will lay the foundation for a new generation of traveling wave tube (TWT) amplifiers for high data rate space communications. The proposed helical TWT for NASA's deep space and earth science missions will be 50% more power efficient than the amplifier on the Cassini mission currently on its way to the environment of Saturn. In addition, the capacity and linearity for digital signal amplification and the reliability of the TWT will be enhanced, while its size, weight, and cooling requirements will be significantly reduced. These dramatic improvements in performance will be achieved by the introduction of four innovations. First, a novel taper will be incorporated that reduces power carried in parasitic waves and increases the main signal. Second, the sever will be eliminated or substantially reduced. Third, a new dielectric support structure is introduced, which reduces the helix temperature by a factor of two. Fourth, a new wire cross-section and advanced materials will further reduce losses. The proposed technology development promises to provide the biggest contribution to efficiency enhancement in helical TWTs since the introduction of velocity tapers some 35 years ago and will enable high frequency digital broadband communications with multi-gigabit-per-second data rates. POTENTIAL COMMERCIAL APPLICATIONS Helical traveling wave tubes are the power amplifiers of choice in satellites for communications, data transmission, broadcasting, and radar mapping. Our advanced technology is expected to have a tremendous impact on the operational cost efficiencies of commercial satellites and the development of broadband, high data rate wireless communications. Additional high volume applications are in satellite ground stations, phased array antennas, microwave power modules, radar for air traffic control and weather forecasting, and medical as well as scientific areas. Military applications include data links, electronic countermeasures, and missile seekers. The successful implementation of the proposed innovations would greatly increase the global competitiveness of the U.S. power tube industry. With the long-standing and extremely successful track record of advanced communications technology pioneered by NASA, this project can be expected to once again lead the way toward record-setting technology with subsequent transfer to and adoption by the commercial communications industry