Mitsubishi Develops Ultra-wideband GaN Doherty Power
Mitsubishi Electric and Mitsubishi Electric Research Laboratories (MERL) have announced their development of an ultra-wideband gallium nitride (GaN) Doherty power amplifier for next generation base stations that is compatible with a world-leading range (company estimate) of frequency bands above 3GHz to cover an operating bandwidth of 600MHz. The technology is expected to help reduce the size and energy consumption of next generation wireless base stations. Technical details will be presented at the IEEE Topical Conference on RF/Microwave Power Amplifiers for Wireless and Radio Applications (PAWR2017) during Radio & Wireless Week (RWW) in the U.S. city of Phoenix, Arizona from January 15-18, 2017.
To help meet a rapid rise in demand for increasing wireless capacity, mobile technologies are shifting to next generation systems that raise capacity by allocating new frequency bands above 3GHz and using multiple frequency bands. Generally, power amplifiers operate with less efficiency in higher frequencies. Also, different power amplifiers are needed for different frequency bands, which can require larger base stations.
As such, extra- efficient power amplifiers compatible with multiple frequencies are in demand.
Mitsubishi Electric's new ultra-wideband GaN Doherty power amplifier uses advanced frequency-compensation circuits with Doherty architecture for enhanced efficiency in a very wide band range. Its efficiency rating of 600MHz above 3GHz was the world's widest level as of January 12, 2017.
The new power amplifier's frequency-compensation circuit enhances efficiency over a wide frequency range to enable wider performance by three times, a world record for Doherty power amplifiers (600MHz). Wideband, high-efficiency performance for efficient amplification of multiple radio frequencies by just one power amplifier will help to reduce base station size and cooling needs. Mitsubishi Electric's high-efficiency GaN devices (MGFS39G38L2) contribute to a world-class drain efficiency of more than 45.9 percent in the 3.0 to 3.6GHz frequency range, thereby reducing energy consumption. Further, an adjacent channel leakage ratio (ACLR) of -50dBc is achieved with a commercial digital pre-distortion (DPD) technique for LTE (Long-Term Evolution) 20MHz signals.