Title :
Design of Symmetrical Class E Power Amplifiers for Very Low Harmonic-Content Applications
Author :
Wong, Siu-Chung ; Tse, Chi K.
Author_Institution :
Dept. of Electron. & Inf. Eng., Hong Kong Polytech. Univ., China
Abstract :
Class E power amplifier circuits are very suitable for high efficiency power amplification applications in the radio-frequency and microwave ranges. However, due to the inherent asymmetrical driving arrangement, they suffer significant harmonic contents in the output voltage and current, and usually require substantial design efforts in achieving the desired load matching networks for applications requiring very low harmonic contents. In this paper, the design of a Class E power amplifier with resonant tank being symmetrically driven by two Class E circuits is studied. The symmetrical Class E circuit, under nominal operating conditions, has extremely low harmonic distortions, and the design of the impedance matching network for harmonic filtering becomes less critical. Practical steady-state design equations for Class E operation are derived and graphically presented. Experimental circuits are constructed for distortion evaluation. It has been found that this circuit offers total harmonic distortions which are about an order of magnitude lower than those of the conventional Class E power amplifier.
Keywords :
differential amplifiers; driver circuits; harmonic distortion; impedance matching; network synthesis; power amplifiers; resonant power convertors; differential amplifiers; driver circuits; harmonic distortions; impedance matching network; low harmonic-content applications; network synthesis; push-pull amplifier; resonant converter; resonant power convertors; resonant tank; steady-state design equations; symmetrical class E power amplifiers; High power amplifiers; Microwave amplifiers; Microwave circuits; Power amplifiers; Power harmonic filters; RLC circuits; Radio frequency; Radiofrequency amplifiers; Resonance; Voltage; Class E power amplifier; harmonic distortion; push-pull amplifier; resonant converter;
Journal_Title :
Circuits and Systems I: Regular Papers, IEEE Transactions on
DOI :
10.1109/TCSI.2005.851723