4:1 bandwidth digital five bit MMIC phase shifters

Abstract

Five-bit monolithic microwave integrated circuits (MMIC) phase shifters that cover over two octaves of bandwidth are developed for functions such as electronic beamsteering and frequency translation. The authors describe two digitally controlled MMIC phase shifters optimized for different operating bandwidths. A lowband version of the phase shifter is designed for the 2.0-6.0-GHz frequency range, and a highband version is designed for the 4.5-18.0-GHz frequency range. Both versions maintain useful performance levels significantly beyond their design bandwidths. The typical measured circuit performance of a highband phase shifter chip in the 4.5-18-GHz band shows a maximum phase error of less than 20 degrees and a +or-1.15-dB maximum change in insertion loss with phase state. The measured circuit performance of a lowband phase shifter chip in the 2.0-6.0-GHz band shows a maximum phase error of less than 15 degrees and less than +or-0.6-dB insertion loss variation with phase state. >