Ultra Wide-band Linearized Doherty Amplifier for Next Generation LTE Base Stations

Mitsubishi Electric US is set to present a hands-on mini lab showcasing its high-efficiency, wide-band GaN Doherty Amplifier at Radio Wireless Week (RWW2018). The event will be held from January 15-16 at the Hyatt Regency Orange County, Garden Grove in California, USA.

At last year’s Radio Wireless Week, Mitsubishi Electric Corporation and Mitsubishi Electric Research Laboratories presented a paper  titled “3.0-3.6 GHz Wideband, over 46% Average Efficiency GaN Doherty Power Amplifier with Frequency Dependency Compensating Circuits,” describing this wide-band Doherty power amplifier design technique for next generation LTE base stations using GaN transistor technology. The demonstration at RWW2018 will further illustrate the ability to linearize an ultra-wideband signal applied to Mitsubishi Electric’s GaN power amplifier using an advanced pre-distortion technique provided by NanoSemi.

The proliferation of smartphones and tablets will require a dramatic increase in wireless capacity of base stations. To meet this demand, mobile technologies are moving to next generation LTE in which the wireless capacities are increased by allocating multiple simultaneous frequency bands (carrier aggregation) above. Operating in multiple simultaneous frequency bands usually requires multiple power amplifiers to cover each frequency band, leading to an increase in the size of base stations.

Conventional base station Doherty power amplifier design presents many challenges to simultaneously achieve both high efficiency and low distortion for wide-band carrier aggregation. Using NanoSemi’s digital pre-distortion (DPD) technology, Mitsubishi Electric’s wide-band Doherty power amplifier can achieve high efficiencies with up to 200MHz instantaneous bandwidth while maintaining ACLR of -50dBc. With this breakthrough, base station designers gain the ability to design a single flexible LTE power amplifier capable of many carrier aggregation scenarios, even above 3GHz.

Mitsubishi Electric’s full line-up of GaN devices, with frequencies in cellular, Ku-, and Ka-bands at output powers ranging from 2 to 100 watts, supports a wide variety of end-communications applications, including cellular base station, satellite, ground station and point to point.