A method of enhancing an electromechanical coupling coefficient of a microelectromechanical (MEMS) device. The method includes applying, to a fully fabricated MEMS device, heavy particle ion radiation to the MEMS device at a fluence of at least 1?10.sup.14 cm.sup.?2. According to other embodiments of the present invention are directed to a bandpass filter comprising a plurality of MEMS devices fabricated in accordance with the methods provided. The MEMS of the plurality are electronically or mechanically coupled.

A method of enhancing an electromechanical coupling coefficient of a microelectromechanical (MEMS) device. The method includes applying, to a fully fabricated MEMS device, heavy particle ion radiation to the MEMS device at a fluence of at least 1?10.sup.14 cm.sup.?2. According to other embodiments of the present invention are directed to a bandpass filter comprising a plurality of MEMS devices fabricated in accordance with the methods provided. The MEMS of the plurality are electronically or mechanically coupled.

Switchable and/or tunable filters, methods of manufacture and design structures are disclosed herein. The method of forming the filters includes forming at least one piezoelectric filter structure comprising a plurality of electrodes formed on a piezoelectric substrate. The method further includes forming a micro-electro-mechanical structure (MEMS) comprising a MEMS beam formed above the piezoelectric substrate and at a location in which, upon actuation, the MEMS beam shorts the piezoelectric filter structure by contacting at least one of the plurality of electrodes.

Switchable and/or tunable filters, methods of manufacture and design structures are disclosed herein. The method of forming the filters includes forming at least one piezoelectric filter structure comprising a plurality of electrodes formed on a piezoelectric substrate. The method further includes forming a micro-electro-mechanical structure (MEMS) comprising a MEMS beam formed above the piezoelectric substrate and at a location in which, upon actuation, the MEMS beam shorts the piezoelectric filter structure by contacting at least one of the plurality of electrodes.

An acoustic wave device includes a piezoelectric layer, first and second comb-shaped electrodes, and a third electrode. The first comb-shaped electrode is on the piezoelectric layer, connected to an input potential, and including a first busbar, and first electrode fingers. The second comb-shaped electrode is on the piezoelectric layer, connected to an output potential, and including a second busbar, and second electrode fingers. The third electrode is connected to a potential different from the first and second comb-shaped electrodes, and includes third electrode fingers, and a connection electrode. The connection electrode interconnects adjacent third electrode fingers. The first electrode finger, the third electrode finger, the second electrode finger, and the third electrode finger are arranged in this order. A ratio d/p is greater than or equal to about 0.05.

An acoustic wave device includes a piezoelectric layer, first and second comb-shaped electrodes, and a third electrode. The first comb-shaped electrode is on the piezoelectric layer, connected to an input potential, and including a first busbar, and first electrode fingers. The second comb-shaped electrode is on the piezoelectric layer, connected to an output potential, and including a second busbar, and second electrode fingers. The third electrode is connected to a potential different from the first and second comb-shaped electrodes, and includes third electrode fingers, and a connection electrode. The connection electrode interconnects adjacent third electrode fingers. The first electrode finger, the third electrode finger, the second electrode finger, and the third electrode finger are arranged in this order. A ratio d/p is greater than or equal to about 0.05.

A bulk-acoustic wave (BAVV) resonator is provided. The BAW includes a substrate, a first electrode disposed on the substrate, a piezoelectric layer disposed to cover at least a portion of the first electrode, and a second electrode disposed to cover at least a portion of the piezoelectric layer, wherein the piezoelectric layer includes an intermediate layer, a first layer disposed above the intermediate layer and a second layer disposed below the intermediate layer, the first layer and the second layer are symmetrical in relation to a plane through which a central line of the intermediate layer passes in a thickness direction, and a thickness of the intermediate layer is greater than a thickness of each of the first and second layers.

A bulk-acoustic wave (BAVV) resonator is provided. The BAW includes a substrate, a first electrode disposed on the substrate, a piezoelectric layer disposed to cover at least a portion of the first electrode, and a second electrode disposed to cover at least a portion of the piezoelectric layer, wherein the piezoelectric layer includes an intermediate layer, a first layer disposed above the intermediate layer and a second layer disposed below the intermediate layer, the first layer and the second layer are symmetrical in relation to a plane through which a central line of the intermediate layer passes in a thickness direction, and a thickness of the intermediate layer is greater than a thickness of each of the first and second layers.

Aspects of this disclosure relate to an acoustic wave filter that includes acoustic wave resonators arranged to filter a radio frequency signal. The acoustic wave resonators include a first acoustic wave resonator. The acoustic wave filter includes a circuit element in parallel with the first acoustic wave resonator in a stage of the acoustic wave filter. The circuit element and the first acoustic wave resonator have different resonant frequencies. The circuit element can reduce an impact of bulk mode of the first acoustic wave resonator on insertion loss of the acoustic wave filter. The first acoustic wave resonator can be a surface acoustic wave resonator in certain embodiments. The circuit element can be a second acoustic wave resonator or a capacitor, for example.

Aspects of this disclosure relate to an acoustic wave filter that includes acoustic wave resonators arranged to filter a radio frequency signal. The acoustic wave resonators include a first acoustic wave resonator. The acoustic wave filter includes a circuit element in parallel with the first acoustic wave resonator in a stage of the acoustic wave filter. The circuit element and the first acoustic wave resonator have different resonant frequencies. The circuit element can reduce an impact of bulk mode of the first acoustic wave resonator on insertion loss of the acoustic wave filter. The first acoustic wave resonator can be a surface acoustic wave resonator in certain embodiments. The circuit element can be a second acoustic wave resonator or a capacitor, for example.