Lise Catherinot

A pressure sensor based on a HBAR micromachined structure

In this work, we propose a pressure sensor fabricated on compound LiNbO3/Silicon/Silicon substrates obtained by Au/Au bonding at room temperature and double face lapping/polishing of LiNbO3/silicon stack and a final gold bonding with a structured silicon wafer. Sensitivity of the final sensor to bending moments then is tested and results show pressure sensitivity of such devices.

Wideband Lithium Niobate FBAR Filters

Filters based on film bulk acoustic resonators (FBARs) are widely used for mobile phone applications, but they can also address wideband aerospace requirements. These devices need high electromechanical coupling coefficients to achieve large band pass filters.The piezoelectric material LiNbO3 complies with such specifications and is compatible with standard fabrication processes. In this work, simple metal--LiNbO3--metal structures have been developed to fabricate single FBAR elements directly connected to each other on a single chip. A fabrication process based on LiNbO3/silicon Au-Au bonding and LiNbO3 lapping/polishing has been developed and is proposed in this paper. Electrical measurements of these FBAR filters are proposed and commented exhibiting filters with 8% of fractional bandwidth and 3.3 dB of insertion losses. Electrical measurements show possibilities to obtain 14% of fractional bandwidth. These devices have been packaged, allowing for power handling, thermal, and ferroelectric tests, corresponding to spatial conditions.

Large band-pass BAW filter for space applications

A resonator using shear waves of lithium niobate is used in this paper to achieve large fractional bandwidth BAW filter. Electromechanical couplings in the 20 − 50 % range are obtained for the shear waves of a thin layer of Lithium Niobate suspended on a silicon substrate. By this way a filter with fractional bandwidth over 20% has been designed for space applications.

Modeling and Design of BAW Resonators and Filters for Integration in a UMTS Transmitter

© 2013 Chatras et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Modeling and Design of BAW Resonators and Filters for Integration in a UMTS Transmitter

BAW pressure sensor on LiNbO 3 membrane lapping

In this paper, we have proposed a new concept for pressure and more generally stress sensors exploiting single-crystal based HBAR. After describing the operation principle, the practical feasibility of the sensor has been shown, yielding electrical results allowing a first characterization of such sensor sensitivity. The process flow is generic and allows us to develop different devices such as HBAR or SAW sensors with the freedom of choosing material in function of the design requirements. Although the first reported results can not exploit the high quality resonance of such HBARs, more effort will be performed in the next future to definitely validate the approach and the corresponding stress sensitivity.

New calibration method for experimental study of nonlinear behavior of Bulk Acoustic Wave resonator with power

This paper deals with experimental studies of nonlinear behavior of Bulk Acoustic Wave (BAW) devices, in a Solidly Mounted Resonator (SMR) structure. The purpose is to extend the Modified Butterworth Van Dyke model to a complete non-linear model of a BAW resonator, which takes into account all nonlinear effects. Frequency shifts were studied when high Radio Frequency (RF) power (up to 5W) is applied to the resonators. We have focused on the W-CDMA frequency standards, for resonators of emission filters of a front-end module in mobile phones. To stabilize the input power, we have developed a new calibration method, which is able to match the data correction between a high and small signal at any frequencies. With this method, we have access to the power waves, and we recalculate the S-parameters externally as a function of the frequency sweep.