Film acoustically-coupled transformer
First Claim
1. A film acoustically-coupled transformer (FACT), comprising:
- decoupled stacked bulk acoustic resonators (DSBARs), each comprising;
a lower film bulk acoustic resonator (FBAR),an upper FBAR stacked on the lower FBAR, each of the FBARs comprising opposed planar electrodes arranged such that a pair of opposed planar electrodes of the lower FBARs are coupled to one another via a trace formed over a cavity, anda piezoelectric element between the electrodes, and between the lower and upper FBARs,an acoustic decoupler comprising a layer of acoustic decoupling material;
first terminals electrically connected to the electrodes of the lower FBARs; and
second terminals electrically connected to the electrodes of the upper FBARs.
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Accused Products
Abstract
One embodiment of the film acoustically-coupled transformer (FACT) includes a decoupled stacked bulk acoustic resonator (DSBAR) having a lower film bulk acoustic resonator (FBAR) an upper FBAR stacked on the lower FBAR, and, between the FBARs, an acoustic decoupler comprising a layer of acoustic decoupling material. Each FBAR has opposed planar electrodes with a piezoelectric element between them. The FACT additionally has first terminals electrically connected to the electrodes of one FBAR and second terminals electrically connected to the electrodes of the other FBAR. Another embodiment has decoupled stacked bulk acoustic resonators (DSBARs), each as described above, a first electrical circuit interconnecting the lower FBARs, and a second electrical circuit interconnecting the upper FBARs. The FACT provides impedance transformation, can linking single-ended circuitry with balanced circuitry or vice versa and electrically isolates primary and secondary. Some embodiments are additionally electrically balanced.
254 Citations
23 Claims
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1. A film acoustically-coupled transformer (FACT), comprising:
decoupled stacked bulk acoustic resonators (DSBARs), each comprising; a lower film bulk acoustic resonator (FBAR), an upper FBAR stacked on the lower FBAR, each of the FBARs comprising opposed planar electrodes arranged such that a pair of opposed planar electrodes of the lower FBARs are coupled to one another via a trace formed over a cavity, and a piezoelectric element between the electrodes, and between the lower and upper FBARs, an acoustic decoupler comprising a layer of acoustic decoupling material; first terminals electrically connected to the electrodes of the lower FBARs; and second terminals electrically connected to the electrodes of the upper FBARs. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A film acoustically-coupled transformer (FACT), comprising:
decoupled stacked bulk acoustic resonators (DSBARs), each of the DSBARs comprising; a lower film bulk acoustic resonator (FBAR), an upper FBAR stacked on the lower FBAR, each FBAR comprising opposed planar electrodes arranged such that a pair of opposed planar electrodes of the lower FBARs are coupled to one another via a trace formed over a filled cavity in a substrate, and a piezoelectric element between the electrodes, and between the lower and upper FBARs, an acoustic decoupler comprising a layer of acoustic decoupling material; a first electrical circuit interconnecting the lower FBARs; and a second electrical circuit interconnecting the upper FBARs. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19)
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20. A film acoustically-coupled transformer (FACT), comprising:
decoupled stacked bulk acoustic resonators (DSBARs), comprising; a lower film bulk acoustic resonator (FBAR), an upper FBAR stacked on the lower FBAR, each of the FBARs comprising opposed planar electrodes arranged such that a pair of opposed planar electrodes of the lower FBARs are coupled to one another via a trace formed over a filled cavity in a substrate, and a piezoelectric element between the electrodes, and between the lower and upper FBARs, an acoustic decoupler comprising a layer of acoustic decoupling material having an acoustic impedance of about 2 Mrayl to about 8 Mrayl, the acoustic decoupler shaped to expose part of the surface of the fill material and patterned to provide access to additional parts of the surface of the fill material; first terminals electrically connected to the electrodes of the lower FBARs via a first electrical circuit; and second terminals electrically connected to the electrodes of the upper FBARs via a second electrical circuit. - View Dependent Claims (21, 22, 23)
Specification