Adjustable 4-Level Hybrid Converter for Symbol Power Tracking in 5G New Radio

A new adjustable multilevel hybrid (AMH) converter architecture is proposed for the radio frequency (RF) amplifier supply modulators using symbol power tracking. The converter comprises a 4-level switched-capacitor stage and an inductive partial-power-processing stage that allows four output levels to dynamically change depending on symbol power and communication traffic patterns in 5G New Radio (NR). The converter prototype provides a wide range of output voltages from 12V to 50V from a 50V input while delivering the output current up to 1A. It achieves efficiency higher than 85% for a wide range of RF loads and can deliver a maximum RF power of 50W with 98.4% efficiency. When tested with a commercial class-AB PA, a power-added efficiency improvement of 3X is achieved at 11 dB backoff power. The converter prototype supports symbol power tracking for 5G NR with a fast level transition below 50ns that is well within the cyclic prefix time allocated to avoid intersymbol interference.