Patent ID: 7423503
Filing Date: 2008-09-09
Classification: H03H

Abstract:
1. An acoustic galvanic isolator, comprising: a carrier signal source; a modulator connected to receive an information signal and the carrier signal; a demodulator; and connected between the modulator and the demodulator, an electrically-isolating acoustic coupler comprising an electrically-isolating film acoustically-coupled transformer (FACT), wherein the FACT comprises: a first decoupled stacked bulk acoustic resonator (DSBAR) and a second DSBAR, each of the DSBARs comprising: a first film bulk acoustic resonator (FBAR); a second FBAR; an acoustic decoupler between the first FBAR and the second FBAR, wherein each of the FBARs comprises an opposed pair of electrodes and a piezoelectric element between the electrodes; and a first electrical circuit interconnecting the first FBARs of the DSBARs in series; and a second electrical circuit interconnecting the second FBARs of the DSBARs in series, wherein the first electrical circuit additionally connects the first FBARs to the modulator, and the second electrical circuit additionally connects the second FBARs to the demodulator; and wherein: the first electrical circuit is connected to the electrodes of the first FBARs remote from the acoustic decouplers; and the second electrical circuit is connected to the electrodes of the second FBARs remote from the acoustic decouplers.