Versatility, Bandwidth and Efficiency: Digital GaN-Based Switch-Mode Supply Modulators

F. Hühn, A. Wentzel, W. Heinrich

Published in:

48th European Microwave Conference (EuMC 2018), Madrid, Spain, Sep. 25-27, pp. 523-526 (2018).

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Abstract:

In this paper the versatility of ultra-fast and, at the same time, high-power capable digital electronics is demonstrated. An electronic switch based on 0.25µm GaN HEMT technology, originally designed as a digital microwave power amplifier, is reconfigured for different applications with the goal of extending the modulation bandwidth and efficiency of envelope tracking concepts. When configured as a DC/DC converter for continuous supply modulation a modulation bandwidth of 300MHz is demonstrated using a clock frequency of 9.4 GHz for the low-pass delta sigma modulator. When configured as a class-G discrete supply modulator, excellent rise and fall times below 112 ps (10% to 90%) are achieved. This allows minimum pulse widths below 1 ns and IQ modulation bandwidth in the GHz range.

Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Berlin, Germany

Keywords:

DC-DC power converters, envelope tracking, RF power amplifiers, switching circuits, supply modulation.