A comprehensive experimental study on technology options for reduced substrate coupling in RF and high-speed bipolar circuits

Abstract

The influence of substrate coupling on advanced high-speed and RF circuits can have a significant impact on circuit performance and must therefore be reduced. Hence, the circuit designer usually applies shielding measures such as guard rings. However, this might not be sufficient for high-performance circuits. Here, also the technology must be optimized to suppress substrate coupling as much as possible. In this work different technology options such as high-resistivity and SOI substrates, transistor isolation techniques, and shielding methods are investigated and their influence on substrate coupling is determined by measurements. In contrast to most previous work, this paper focuses on high-speed and RF circuits, fabricated in advanced bipolar or BiCMOS technologies.