Mitsubishi Electric, Nokia Bell Labs, UC San Diego Develop World’s First Ultra-Fast GaN Envelope-tracking Power Amplifier for Next-generation Wireless Base Stations

High-speed operation of envelope-tracking power amplifier will help
reduce energy consumption of next-generation wireless base stations

Electric Corporation
(TOKYO:6503), Nokia Bell Labs and the Center
for Wireless Communications at UC San Diego announced today their joint
development of the world’s first ultra-fast gallium nitride (GaN)
envelope-tracking power amplifier, which supports modulation bandwidth
up to 80MHz and is expected to reduce energy consumption in
next-generation wireless base stations. Technical details will be
presented during the IEEE MTT International Microwave Symposium (IMS)
2017, which will be held in Honolulu, Hawaii, USA from June 4 to 9.

To help meet the demand for increasing wireless capacity, mobile
technologies are shifting to next-generation systems that use complex
modulated signals with large peak-to-average power ratio (PAPR) and
extra-wide modulation bandwidth. This will require power amplifiers to
operate most of the time at backed-off power levels that are well below
their saturation levels. Generally, power amplifiers achieve high
efficiency near their saturation power levels, but significantly
degraded efficiency at backed off levels, as in the case of 4G LTE*
signals (>6dB PAPR). Envelope-tracking power amplifiers have been
studied extensively as a means to enhance power-amplifier efficiency,
but so far the supply-modulator circuit has been the bottleneck limiting
modulation bandwidth for advanced wireless communications, such as

The newly developed ultra-fast GaN envelope-tracking power amplifier
achieves state-of-art performance thanks in part to Mitsubishi
Electric’s high-frequency GaN transistor technology and design
innovation for the GaN supply-modulator circuit. Using Nokia Bell Labs’
real-time digital pre-distortion (DPD) system, the power amplifier has
demonstrated efficient operation even with 80MHz modulated LTE signals,
the world’s widest modulation bandwidth for this purpose as of May 19,

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Mitsubishi Electric
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Mitsubishi Electric Corporation
Takeyoshi Komatsu
Relations Division