Laterally-coupled acoustic resonators

Abstract

An apparatus, comprises a piezoelectric layer, a first acoustic resonator comprising first and second electrodes formed on opposite sides of the piezoelectric layer, and a second acoustic resonator comprising first and second electrodes formed on opposite sides of the piezoelectric layer and acoustically coupled to the first acoustic resonator.

1 . An apparatus, comprising:
 a piezoelectric layer;   a first acoustic resonator comprising first and second electrodes formed on opposite sides of the piezoelectric layer; and   a second acoustic resonator comprising first and second electrodes formed on opposite sides of the piezoelectric layer and acoustically coupled to the first acoustic resonator, wherein the respective first electrodes of the first and second acoustic resonators are electrically separated from each other and the respective second electrodes of the first and second acoustic resonators are electrically connected to each other.   
     
     
         2 . An apparatus as claimed in  claim 1 , the first electrode of the first acoustic resonator comprising a first electrode bus connected to a first plurality of finger structures; and the first electrode of the second acoustic resonator comprising a second electrode bus connected to a second plurality of finger structures, wherein the respective second electrodes do not overlap either the first electrode bus or the second electrode bus. 
     
     
         3 . An apparatus as claimed in  claim 1 , wherein portions of each of the first and second electrodes overlap with each other to define an active region, and the first and second electrode buses are located outside the active region. 
     
     
         4 . An apparatus as claimed in  claim 3 , wherein the first and second pluralities of fingers have a first thickness, and the first and second electrode buses have a second thickness greater than the first thickness. 
     
     
         5 . An apparatus as claimed in  claim 4 , wherein the second thickness is adapted to maintain a resonance associated with the first and second electrode buses away from the passband.