Fully Differential 90 GHz and 180 GHz Signal Sources With Tuning Ranges of 24.1 GHz and 51.7 GHz in 90 nm SiGe-BiCMOS

Currently, commercial radar systems are mainly found in the E-band. However, higher frequencies offer significant advantages in terms of absolute bandwidth and system design. The use of on-chip antennas and FR4 PCB materials is enabled by frequencies above $\approx$100GHz. This work presents two wideband and fully integrated signal sources for radar applications at 90 and 180 GHz. By using the novel 90nm SiGe BiCMOS B12HFC technology, the signal sources provide up to 6.43 dBm and 3.8 dBm output power and dc-to-RF efficiencies of 4.59% and 0.98%, respectively. Furthermore, the two signal sources achieve a tuning range of 24.1 GHz (26.6%) and 51.7 GHz (28.8%). The 90 GHz signal source is based on a fundamental voltage-controlled oscillator and a static by-16 frequency divider, which operates up to 120 GHz. The divided LO signal allows the use of commercial PLL components to enable different modulation schemes. The 180GHz signal source uses the same building blocks but is extended by a power amplifier and a bootstrapped Gilbert-Cell-based frequency doubler, which has a differential output.