Of filters
AssigneeTDK Corporation
InventorsRoger W. Whatmore, Paul B. Kirby, Qingxin Su, Eiju Komuro
Life of this patent
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Abstract
An electric filter comprises a plurality of thin film bulk acoustic resonants (10, 11) arranged in series and in parallel which have electrodes (24, 25) of different working area (L) and optionally a piezoelectric layer (23) of different thickness (T).
Claims17
An electric filter comprising a plurality of thin film bulk acoustic resonators (FBARs) consisting of a thin layer of a piezoelectric material sandwiched between two metal electrodes linked in a series/parallel connection arrangement for which the areas of the electrodes in contact with the piezoelectric layer to form the resonators are different between in series and in parallel FBARs.
An electric filter as described in any preceding claim, wherein the piezoelectric material is zinc oxide.
An electric filter as described in any preceding claim, wherein the metal electrodes comprise gold.
An electric filter as described in any preceding claim, wherein 2 FBARs are linked in series and 2 FBARs are linked in parallel.
An electric filter according to any preceding claim, wherein the piezoelectric material of FBARs in parallel is thicker than that of FBARs in series.
An electric filter according to any preceding claim, wherein the area of electrodes of FBARs in parallel is greater than that of FBARs in series.
An electric filter comprising at least one FBAR in series and at least one FBAR in parallel, each FBAR comprising a layer of piezoelectric material sandwiched between two electrodes of which the areas of the electrodes in contact with the piezoelectric layer are different between the FBAR in series and the FBAR in parallel.
An electric filter substantially as hereinbefore described with reference to the accompanying drawings.
Dependencies are inferred from the claim text.