Nonlinear effects in acousto-electric devices

Abstract

This work deals with the nonlinear behavior of acousto-electric components. Besides the well known surface acoustic wave (SAW) components also bulk acoustic wave (BAW) devices are meanwhile used in the RF front-end of mobile phones. Especially duplexers have to face the challenge of handling high-power Tx signals together with low-power Rx signals. In order to investigate the nonlinear behavior of such devices single resonators are studied in detail first. Increasing the resonator area by means of cascading lowers the power density on the surface and allows for lower input intercept points of second and third order, IIP2 and IIP3. This investigation gives a first proposal about how to improve current available BAW duplexers. In advance SAW and BAW duplexers of various vendors are measured and compared to each other with respect to their IIP2 and IIP3 values for the very first time. These measurements have been performed at the 3GPP Band II frequency band, which has the same frequency allocation (Tx: 1850 - 1910 MHz, Rx: 1930 - 1990 MHz) like the IS-95 system.