MTL Annual Research Report 2012 » alexander jurkov http://www-mtl.mit.edu/wpmu/ar2012 Call for Titles Thu, 01 Nov 2012 17:15:28 +0000 en-US hourly 1 http://wordpress.org/?v=3.5.1 Lossless Multi-Way Power Combining and Outphasing for Radio-Frequency Power Amplifiers http://www-mtl.mit.edu/wpmu/ar2012/lossless-multi-way-power-combining-and-outphasing-for-radio-frequency-power-amplifiers/ http://www-mtl.mit.edu/wpmu/ar2012/lossless-multi-way-power-combining-and-outphasing-for-radio-frequency-power-amplifiers/#comments Wed, 18 Jul 2012 22:27:16 +0000 MTL WP admin http://www-mtl.mit.edu/wpmu/ar2012/?p=5852

For applications requiring the use of power amplifiers (PAs) operating at high frequencies and power levels, it is often preferable to construct multiple low-power PAs and combine their output powers to form a high-power PA. Moreover, such PAs must often be able to provide dynamic control of their output power over a wide range and maintain high efficiency across their operating range. This research work introduces a new power combining and outphasing system that provides both high efficiency and dynamic output power control [1] . The system combines power from four or more PAs (Figure 1) and overcomes the loss and reactive loading problems of previous outphasing systems [2] [3] [4] . It provides ideally lossless power combining, along with nearly-resistive loading of the individual power amplifiers over a very wide output power range. The theoretical fundamentals underlying the behavior and operation of this new combining system were thoroughly developed. Additionally, a straight-forward combiner design methodology was provided. The prototype design of a 27.12 MHz, four-way power combining and outphasing system was presented and implemented (Figure 2), and its performance was experimentally validated over a 10W-100W (10:1) output power range [5] .

Figure 1 Figure 2
  1. A. S. Jurkov and D. J. Perreault, “Design and control of lossless multi-way power combining and outphasing systems,” Midwest Symposium on Circuits and Systems, pp. 1-4, Aug. 2011. =
  2. H. Chireix, “High power outphasing modulation,” Proc, of the IRE, vol. 23, no. 11, pp. 1370-1392, Nov. 1935.
  3. F. H. Raab, “Efficiency of outphasing RF power-amplifier systems,” IEEE Transactions on Communications, vol. 33, no. 9, pp. 1094-1099, Oct. 1985.
  4. A. Birafane and A. Kouki, “On the linearity and efficiency of outphasing microwave amplifiers,” IEEE Transactions on Microwave Theory and Techniques, vol. 52, no. 7, pp. 1702-1708, July 2004.
  5. A. S. Jurkov and D. J. Perreault, “Lossless multi-way power combing and outphasing for high-frequency resonant inverters,” IEEE Transactions on Power Electronics and Motion Control, to be published
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