A Novel Model for Digital Predistortion of Discrete Level Supply-Modulated RF Power Amplifiers

N. Wolff, W. Heinrich, and O. Bengtsson

Published in:

IEEE Microwave Wireless Compon. Lett., vol. 26, no. 2, pp. 146-148 (2016).

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Abstract:

The linearization of a discrete level supplymodulated RF power amplifier using digital predistortion (DPD) is investigated. The characteristics of the system are evaluated and a novel DPD model, capable of handling the switching dynamics of the system, is developed and presented. The model is tested for an RF power amplifier operating at 2.65 GHz with a 16 MHz modulated signal. It is shown that modeling the supply voltage transitions with the novel model significantly improves linearity by up to 1.6 dB NMSE and 3.3 dB in ACLR. With the novel model DPD on the supply modulated PA can achieve similar linearity as a single supply PA but with much improved PAE.

Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Straße 4, 12489 Berlin, Germany

Index Terms:

Digital predistortion (DPD), discrete level supply modulation, linearization, RF power amplifiers (PAs).