HIGH EFFICIENCY RADIO FREQUENCY POWER AMPLIFIER WITH DYNAMIC LOAD MODULATION FOR WIRELESS COMMUNICATIONS

초록

In this article, a radio frequency (RF) power amplifier (PA) with high efficiency and high linearity is presented by using dynamic load modulation (DLM) technique. To improve the average efficiency, the load impedance is dynamically modulated according to the input envelop using tunable matching circuit (TMC). The TMC using varactors is located at a low-impedance region of the output matching network. This reduces the RF voltage swing across the varactors, which minimizes the performance degradation by the varactors. The measurement setup is constructed to generate a control signal for the TMC that is synchronized with an input envelope. For wideband code division multiple access (W-CDMA) signal with a peak-to-average ratio of 7.4 dB and a bandwidth of 3.84 MHz at 1.85 GHz, the fabricated DLM PA shows a power-added efficiency of 49.7% at an output power of 30.6 dBm with an adjacent channel leakage ratio of <-45 dBc (C) 2016 Wiley Periodicals, Inc.

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