Sources of Phase Error and Design Considerations for Silicon-Based Monolithic High-Pass/Low-Pass Microwave Phase Shifters

A comprehensive analysis of error sources in monolithic microwave phase shifters due to device size limitations, inductor parasitics, loading effects, and nonideal switches is presented. Each component utilized in the implementation of a monolithic high-pass/low-pass phase shifter is analyzed, and its influence on phase behavior is shown in detail, with an emphasis on the net impact on absolute phase variation. The design of the individual phase-shifter filter sections and the influence of bit ordering on overall performance are also addressed. An X-band 5-bit phase shifter fabricated in a 200-GHz SiGe HBT BiCMOS technology platform is used to validate this analysis and our design methodology and achieves an absolute rms phase error of 4deg and relative rms phase error of 3deg for operation from 8.5 to 10.5 GHz