Lüder Elbrecht

Bulk-acoustic-wave filters: performance optimization and volume manufacturing

Performance parameters of BAW devices are reviewed and ranked corresponding to their importance for RF-filters in mobile phone applications. The most important performance parameters - such as resonator bandwidth and Q-values - critically depend on the quality of the piezolayer and other relevant layers in the acoustic stack. The design of the complete layer stack in a Solidly Mounted Resonator (SMR) concept in combination with a proper design of lateral resonator-boundaries will be revealed to be extremely important for the suppression of spurious resonances. Challenges in manufacturing of BAW filters will be briefly reviewed. Examples of state-of-the-art in BAW filters in production and ramp-up status will be presented.

Integration of bulk acoustic wave filters: concepts and trends

The concepts and trends for the use of bulk acoustic wave (BAW) filters in tomorrows highly integrated RF front end components in mobile communication devices are discussed. We present examples for the integration of BAW filters into low-cost laminate-based modules and for the monolithic integration of solidly mounted bulk acoustic wave devices with bipolar integrated circuits. The options and limitation of the integration approaches are discussed.

An Integrated Gravimetric FBAR Circuit for Operation in Liquids Using a Flip-Chip Extended 0.13μm CMOS Technology

A 0.13μm CMOS chip is fabricated with eight resonator-amplifiers to demonstrate a highly integrated gravimetric sensor based on an FBAR oscillator. The oscillator is attached via flip-chip bonding to a CMOS resonator. Each active 1.86GHz oscillator draws 27mA from a single 17V supply for 200×200μm2 sensors. The resonance frequency shifts by 5MHz in ethanol and 7.3MHz in water and jitter is <3kHz