Resolving mMIMO Power Amplifier Design Efficiency and Linearity Challenges with Industry Leading Wideband Digital Pre-Distortion Systems

Massive multiple-input-multiple-output (mMIMO) system designers are being challenged to improve overall system efficiency. With instantaneous bandwidths at 200 MHz and greater, it is increasingly important to reduce the distortion created when operating Power Amplifiers (PA) in their non-linear region. Balancing wide-band system linearity with the system efficiency is a must-meet metric to fit the size, weight, and power requirements of mMIMO systems. To design such a wide-band system around given linearity requirements, the optimization of the design should look beyond the final-stage PA and expand focus to the entire amplification lineup. Similarly, this amplification lineup should be optimized with the system transceiver and Digital Pre-Distortion (DPD) algorithm in mind.In a collaboration between Wolfspeed and Analog Devices, Inc. (ADI), we take a deeper look at the balance between efficiency and linearity by discussing industry approaches and presenting examples in the following areas:

• Choosing higher efficiency device technologies, i.e. Gallium Nitride (GaN) on Silicon Carbide (SiC), for amplifier lineups.
• Application specific DPD systems for simple and highly efficient lineup architectures.