Ultra-High Power and Efficiency Space Traveling-Wave Tube Amplifier Power Combiner With Reduced Size and Mass for NASA Missions

• Published in: IEEE transactions on microwave theory and techniques Vol. 57; no. 3; pp. 582 - 588
• Main Authors: Simons, R.N., Wintucky, E.G., Wilson, J.D., Force, D.A.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.03.2009; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Amplifiers; Applied sciences; Circuit design; Circuit properties; Communication systems; Data transmission; Efficiency; Electric, optical and optoelectronic circuits; Electronic circuits; Electronic tubes, masers; Electronics; Exact sciences and technology; K-band; Keying; magic-T; Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; microwave power amplifiers; Microwaves; millimeter wave power amplifiers; millimeter wave tubes; NASA; Phase shift keying; Power amplifiers; power combiner; Power combiners; power conditioning; Quadrature phase shift keying; Radio frequencies; Radio frequency; Radiofrequency amplifiers; satellite communication; Satellite telecommunications. Space telecommunications; Space exploration; Space missions; space technology; Telecommunications; Telecommunications and information theory; Traveling wave tubes; traveling-wave tubes (TWTs); Ultra wideband technologies; waveguide; Performance evaluation; Microwave device; millimeter wave tubes; Circuit design; millimeter wave power amplifiers; Travelling wave amplifier; Bit error rate; Space telecommunication; K band; Wireless telecommunication; Microwave; Data transmission; Travelling wave tube; Power combiners; satellite communication; Microwave amplifier; Low bit rate; magic-T; NASA; traveling-wave tubes (TWTs); space technology; Centimetric wave; power combiner; Binary phase shift keying; Amplifiers; microwave power amplifiers; Waveguide; Information transmission; power conditioning; Quadrature phase shift keying; Combiner circuit; High power; Ka band; Miniaturization; Figure of merit
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/TMTT.2008.2012298

In the 2008 IEEE Microwave Theory and Techniques Society International Microwave Symposium Digest version of our paper, recent advances in high power and efficiency space traveling-wave tube amplifiers for NASA's space-to-Earth communications are presented. The RF power and efficiency of a new K-band amplifier are 40 W and 50% and that of a new K-band amplifier are 200 W and 60%. An important figure-of-merit, which is defined as the ratio of the RF power output to the mass (W/kg) of a traveling-wave tube (TWT), has improved by a factor of 10 over the previous generation Ka-band devices. In this paper, a high power high efficiency Ka -band combiner for multiple TWTs, based on a novel hybrid magic-T waveguide circuit design, is presented. The measured combiner efficiency is as high as 90%. In addition, at the design frequency of 32.05 GHz, error-free uncoded binary phase-shift keying/quadrature phase-shift keying (QPSK) data transmission at 8 Mb/s, which is typical for deep-space communications, is demonstrated. Furthermore, QPSK data transmission at 622 Mb/s is demonstrated with a low bit error rate of 2.4 times10 -8 , which exceeds the deep-space state-of-the-art data rate transmission capability by more than two orders of magnitude. A potential application of the TWT combiner is in deep-space communication systems for planetary exploration requiring transmitter power on the order of a kilowatt or higher.