Device Design And Application Based On Film Bulk Acoustic Wave Technology

The rapid development of wireless telecommunication has greatly stimulated the demand for multi-frequency transceivers or receivers,with the purpose of synchronously processing a large amount of data.In recent years,multi-frequency transceivers or receivers have been widely exploited in positioning systems and multi-standard systems,where different frequency bands collaborate to improve the performance of the system.Although the frequency bands increase in a single chip,the general trend towards miniaturization continues as consumer demand for smaller and more feature-rich portable devices emerge,which poses a limitation to the size of filters.The traditional waveguide technology,generally used to realize the multiband filter,is too bulky to satisfy this demand in mobile devices.In order to meet the enormous challenges,more attentions have been focused on the emerging film bulk acoustic wave resonator(referred to as FBAR)technology,which is known for its intrinsic superiority in quality factor,power handling capability,and compatibility with the standard integrated circuit(IC)processing.This thesis starts from discussions of the theoretical basis of thin film bulk acoustic resonator.Then the thesis analyses electric MBVD model and physical Mason model of FBAR and focuses on FBAR filter design method based on two-port network.The design method of FBAR dual-passband filter is introduced in details and the measured results are showed,which are in agreement with the simulated ones.The dual-passband filter is achieved by two band-pass FBAR filters with shared input and output ports.A simple matching network is used to provide high performance dual-passband response with little mutual degeneration.The measured insertion loss is around 2.0 dB typically in both the lower and the upper passbands,and the filter rejections out of the passbands are more than 30 dB.A smart wide-band low-loss FBAR filter topology is also proposed with great value in engineering aplllication,introducing a special shunt branch to adjust zero postion.The measured return loss of the filter is less than-15 dB and the measured out-of-band rejection is more than 40 dB.