Integration Issues Associated with Monolithic Silicon-Germanium Microwave Radar Systems

Abstract

Active electronically scanned array (AESA) radar systems for military and commercial applications have fueled interest in low-cost, high-performance technologies capable of delivering integrated circuits for transmit-receive (T/R) modules and monolithic radar systems. Silicon-Germanium (SiGe) Heterojunction Bipolar Transistor (HBT) technology has been flagged as a strong candidate for such applications because of its high-speed low-noise devices, high integration capabilities, and relatively low cost.

This work investigates integration issues associated with monolithic silicon-germanium radar systems for military (8-12 GHz) and automotive (24 GHz) applications. The design and implementation of critical circuits, such as phase shifters, power amplifiers, up-conversion mixers, down-conversion mixers, and voltage-controlled oscillators will be investigated, along with the system level considerations associated with these components. These building blocks have been fabricated and tested at wafer level, utilizing commercially available SiGe HBT BiCMOS technologies, demonstrating acceptable performance for these applications. Preliminary research into substrate coupling associated with these BiCMOS technologies will also be presented, demonstrating the potential for circuit-to-circuit substrate coupling to occur at these microwave frequencies.