• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.6
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• pp.613-622
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• 2013

In this paper, an inductive clamping class-E power amplifier has been tested for wireless power transmission at ISM band, 13.56 MHz. The implemented power amplifier is designed to operate stably without destroying power transistor in wireless power transmission system which basically keeps not to align between a transmitting antenna and a receiving antenna. The power amplifier is also designed to enhance harmonic filtering characteristic. The amplifier was tested with a DC supply voltage of 28 V and input power of 25 dBm at 13.56 MHz. The test results show the output power level of 43 dBm, the difference power level between fundamental frequency and second harmonic frequency of more than 55 dBc, the dc current consumption of 830 mA, and the high power-added efficiency of 85 %. Finally, the implemented power amplifier operated normally with 830 mA DC current consumption from 28 V source when the two antennas were aligned, and the power transmission was successful. But when the two antennas were not aligned, its DC current consumption automatically decreased down to 420 mA to protect the switching transistor.