Linearity Measurements of Intrinsically Switchable BST FBAR Filters

Abstract

The linearity of intrinsically switchable thin film bulk acoustic wave resonator (FBAR) filters based on ferroelectric barium strontium titanate (BST) is investigated. A 2.5 stage ladder type BST FBAR filter is designed and fabricated with an insertion loss of 4.3 dB and a fractional bandwidth of 2.5% at the center frequency of 2.2 GHz. Third-order intercept point $(\mathbf{IP}_{\mathbf{3}})$ measurements are conducted to characterize the linearity of the filter. The measured $\mathbf{IIP}_{3}$ value for the filter is 47 dBm.