Efficient RF-PA Two-Chip Supply Modulator Architecture for 4G LTE and 5G NR Dual-Connectivity RF Front-End

Abstract

This paper presents a two-chip supply modulation architecture for efficient RF power amplification using a fully switched-mode supply modulator (SM) and a linear-assisted hybrid SM to support simultaneous transmission on LTE and 5G bands. The designed fully switched-mode SM consists of a fast buck converter and a slow buck converter, and it achieves 88.2% peak efficiency with a low RX band noise of -140dBm/Hz at the SM output. The designed 5G NR SM, consisting of a class-AB linear amplifier (LA) and an interleaved 3-level buck-boost converter provides a 150-MHz 3-dB bandwidth for tracking the 100-MHz envelope signal. An optimal RF-PA supply deployment using the two SMs efficiently supports multiple RF-PA loads while satisfying the dual transmission requirements of E-UTRAN New Radio Dual-Connectivity (EN-DC) and 5G 100-MHz ET operation.