Preparing Linearity and Efficiency for 5G: Digital Predistortion for Dual-Band Doherty Power Amplifiers with Mixed-Mode Carrier Aggregation

As new wireless communication standards seek to meet the myriad demands of today's end users, the traditional RF transmitter chain is faced with an evolving set of challenges. To maximize information throughput, signal bandwidths are continuously growing. In fourth-generation longterm evolution-advanced (also called LTE-A), for example, to meet the stated goals of 1-Gb/s downlink and 500-Mb/s uplink speeds, the carrier aggregation (CA) technique was introduced, expanding the maximum transmit bandwidth up to 100 MHz [1]. With mobile traffic expected to increase by a factor of 1,000 over the next decade, future fifth-generation (5G) systems will continue to place new demands on the transmit chain [2].