5.4 GHz, 0.35 µm BiCMOS FBAR-Based Single-Ended and Balanced Oscillators in Above-IC Technology
Résumé
This chapter deals with the world premiere realization of two 5-GHz FBAR-based oscillators, where the FBAR is directly integrated above the IC with some further process steps, compatible with (Bi)CMOS. A single-ended and a balanced version were designed. The circuits were implemented in a 0.35-μm SiGe BiCMOS process from AMI Semiconductor. From the obtained results, we show that post-processing the FBAR directly over the IC eliminates much of the parasitics and modelling issues associated with bondwires. Furthermore, it reduces the circuit area. The single-ended and balanced oscillators are based on the Colpitts configuration and achieve respectively a state-of-the-art phase noise performance (at the time of design) of −117.7dBc/Hz and −121dBc/Hz at 100kHz offset from the 5.4-GHz carrier frequency. The balanced version allows direct driving of balanced dividers and mixers without the need of a single-ended to balanced converter. Some comparisons are also made with standard LC balanced oscillators.