Radio-Frequency Inverters With Transmission-Line Input Networks

A soft-switching inverter topology (the Class Phi ) is presented which draws dc source current through a transmission line or a lumped-network approximation of a distributed line. By aligning the inverter switching frequency just below the line's lambda/4-wave resonance, the Class Phi topology enforces odd-and even-harmonic content in its drain voltage and input current, respectively. The symmetrizing action of the transmission-line dynamics results in natural square-wave operation of the switch, reducing the inverter stresses (relative to a Class E) for a given power throughput. The inverter waveforms and normalized power-output capability are analyzed in simple terms, and supported by measurements of an inverter built around a length of distributed line, and an inverter incorporating a lumped L-C ladder network. The latter implementation is constructed with air-core magnetics and inter-layer capacitances that are integrated into the thickness of a printed-circuit board. A comparison with a Class E inverter of similar size and ratings demonstrates the small passive-component values and manufacturing advantages afforded by the Class Phi topology.

[1]  Ali Hajimiri,et al.  The class-E/F family of ZVS switching amplifiers , 2003 .

[2]  R. J. Gutmann,et al.  Power Combining in an Array of Microwave Power Rectifiers , 1979 .

[3]  N. O. Sokal,et al.  Harmonic output of class-E RF power amplifiers and load coupling network design , 1977 .

[4]  Thomas H. Lee,et al.  The Design of CMOS Radio-Frequency Integrated Circuits: RF CIRCUITS THROUGH THE AGES , 2003 .

[5]  Yehui Han,et al.  Resistance Compression Networks for Resonant Power Conversion , 2005, 2005 IEEE 36th Power Electronics Specialists Conference.

[6]  Kazuhiko Honjo,et al.  A simple circuit synthesis method for microwave class-F ultra-high-efficiency amplifiers with reactance-compensation circuits , 2000 .

[7]  F. H. Raab,et al.  Class-F power amplifiers with reduced conduction angles , 1998, IEEE Trans. Broadcast..

[8]  D.J. Perreault,et al.  Multi-resonant microfabricated inductors and transformers , 2004, 2004 IEEE 35th Annual Power Electronics Specialists Conference (IEEE Cat. No.04CH37551).

[9]  H. Zirath,et al.  L-band LDMOS power amplifiers based on an inverse class-F architecture , 2005, IEEE Transactions on Microwave Theory and Techniques.

[10]  D.J. Perreault,et al.  New architectures for radio-frequency DC/DC power conversion , 2004, 2004 IEEE 35th Annual Power Electronics Specialists Conference (IEEE Cat. No.04CH37551).

[11]  Joshua W. Phinney,et al.  Multi-resonant passive components for power conversion , 2005 .

[12]  E. Guillemin.  Synthesis of passive networks : theory and methods appropriate to the realization and approximation problems , 1957 .

[13]  D.J. Perreault,et al.  Synthesis of Lumped Transmission-Line Analogs , 2007, IEEE Transactions on Power Electronics.

[14]  David J. Perreault,et al.  Filters with active tuning for power applications , 2003 .

[15]  D. M. Snider,et al.  A theoretical analysis and experimental confirmation of the optimally loaded and overdriven RF power amplifier , 1967 .

[16]  F. Raab.  Maximum efficiency and output of class-F power amplifiers , 2001 .

[17]  F. Raab.  Class-F power amplifiers with maximally flat waveforms , 1997 .

[18]  No Sokal,et al.  CLASS-E - NEW CLASS OF HIGH-EFFICIENCY TUNED SINGLE-ENDED SWITCHING POWER AMPLIFIERS , 1975 .