Description: Space telecommunications require amplifiers that are efficient, high-power, wideband, small, lightweight, and highly reliable. Currently, helix traveling wave tube amplifiers (TWTA) are the technology of choice. Conventional helix TWTAs employ circular electron beams. Recently, lightweight circular-beam helix TWTAs have been demonstrated with power output in the range of several hundred watts and overall efficiency in the range of 40 to 60 percent. Despite these advances, there is substantial value in further improvement across all of these areas. Beam Power Technology (BPT) proposes a novel elliptic-beam TWTA which is highly efficient (75%) and has 500 W of CW power, reduced weight, lower voltage and an expected 15+ year lifetime. The average power operation is at a back-off of -6 dB from saturation. The linearity is -35 dBc. The Phase I objective is to determine the feasibility of an elliptic-beam helix TWTA which substantially exceeds the performance levels of conventional helix devices. In Phase II, BPT will complete the engineering design and experimental demonstration of a prototype targeting eventual deployment into satellite applications.

Benefits: Elliptic-beam helix TWTAs have applications in rf amplification requiring high efficiency, high power, broad bandwidth and lower cost. Key markets will be commercial satellite communications, both space and ground stations, military radar and communications and non-lethal weapons systems, and commercial wireless base station amplifiers. This technology can be used to increase performance of all vacuum electron devices (VEDs) that use linear beams such that it will revitalize the market for highly reliable high power VEDs.

The elliptic-beam helix TWTA will provide NASA deep space missions with both increased efficiency and increased power over current state of the art rf transmitters while reducing weight, volume, voltage and complexity. In general, high-efficiency, high-power elliptic-beam TWTAs align with NASA's vision for space exploration by increasing the science data rate-of-return for exploration missions, and by enabling deeper, more sophisticated exploration of the solar system. In particular, high-efficiency, high-power elliptic-beam TWTAs would benefit the R&D programs in the NASA Glenn Research Center's Exploration Systems Division.