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The Journal of The Korea Institute of Intelligent Transport Systems Vol.9 No.2 pp.51-59
출력 전력 백-오프 기반 비대칭 도허티 전력 증폭기
Output Power Back-Off(OPBO) Based Asymmetric Doherty Power Amplifier
Abstract
In this paper, we propose an inverted type asymmetric Doherty amplifier with optimized efficiency characteristic in wanted output power back-off (OPBO) range according to peak to average power ratio of input signal In order to obtain optimized efficiency of the asymmetric Doherty amplifier in wanted OPBO, peak power ratio between main amplifier and peaking amplifier was determined and then impedance of 90 degrees impedance transformer was obtained by peak power ratio. The offset line length and peak dividing ratio of the asymmetric Doherty amplifier were also calculated. From the measurement results, the proposed amplifier has achieved 40 % drain efficiency and -35 dBc adjacent channel leakage ratio at the average output power of 48.7 dBm for CDMA 2000 1x 3-FA test signal.
