A Switch-Bank Approach for High-Power, High-Resolution, Fully-Digital Transmitters

Abstract

An implementation strategy for high-power, high resolution, fully digital transmitters (DTX) is proposed. It is based on a high-speed CMOS controller featuring a high-density flip-chip interconnect to an LDMOS power MMIC containing large arrays of custom low-VT LDMOS gate segments configured in RF-power switch banks. Using a two-level thermometer approach and a novel symmetric control scheme for the activation of the gate segments, a high-resolution 11-bit DTX switch bank is realized. It can provide peak RF powers >10 W at 45/40% peak drain/system efficiency at 3.525 GHz.