Murata Manufacturing Co., Ltd.

Resonant, Inc.

Greg Dyer

Neal O Fenzi

Bryant Garcia

Sean McHugh

Andrew C Guyette

Robert B Hammond

Chris O'Brien

Patrick J Turner

Ventsislav Yantchev

James R Costa

Viktor Plesski

Julius Koskela

Ryo Wakabayashi

Soumya Yandrapalli

Jesson John

Albert Cardona

Douglas Jachowski

Wei Yang

Luke Myers

Andrew Kay

John Pandelis Koulakis

Doug Jachowski

Marie Chantal Mukandatimana

Dylan J Kelly

Garrett Williams

Gregory L Hey-Shipton

Filip Iliev

Kuan Zhang

Chris O′Brien

An apparatus for filtering radio frequency signals is provided. The apparatus includes a substrate and a membrane coupled to the substrate that includes piezoelectric material. The apparatus also includes an interdigital transducer (IDT) coupled to the membrane and includes a plurality of interleaved fingers. The apparatus also includes a lid, in which the membrane is arranged between the substrate and the lid with a first cavity having a first height between the lid and a first main surface of the membrane and a second cavity having a second height between the substrate and a second main surface of the membrane that opposes the first main surface. Moreover, the first height between the lid and the first main surface of the membrane is greater than a pitch of at least one pair of interleaved fingers of the plurality of interleaved fingers and at most four times greater than the second height.

Acoustic resonator lid for thermal transport

A filter device is provided that includes a substrate having a surface and a piezoelectric plate supported by the substrate. A plurality of interdigital transducers (IDTs) for multiple resonators are provided that each have interleaved fingers at respective diaphragms of the piezoelectric plate disposed over one or more cavities. Moreover, a first resonator includes a first plurality of interleaved fingers having a first pitch and a second resonator includes a second plurality of interleaved fingers having a second pitch that is different than the first pitch. This configuration adjusts the resonance frequencies of each resonator. Moreover, a dielectric layer may be uniformly disposed over at least one surface of the respective diaphragms of the piezoelectric plate.

Ladder filter with transversely-excited film bulk acoustic resonators having different pitches

Acoustic resonator devices and acoustic filter devices. An acoustic resonator includes a piezoelectric plate having front and back surfaces. The back surface is attached to a surface of a substrate. The piezoelectric plate comprises a diaphragm spanning a cavity. A conductor pattern is formed on the front surface. The conductor pattern includes a multi-mark multi-pitch interdigital transducer (IDT), wherein fingers of the IDT are on the diaphragm.

Transversely-excited film bulk acoustic resonator with multi-mark, multi-pitch interdigital transducer

Filter devices are disclosed. A filter device includes a piezoelectric plate comprising a supported portion, a first diaphragm, and a second diaphragm. The supported portion is attached to a substrate and the first and second diaphragms spans respective cavities in the substrate. A first interdigital transducer (IDT) has interleaved fingers on the first diaphragm. A second interdigital transducer (IDT) has interleaved fingers on the second diaphragm. A first dielectric layer is between the interleaved fingers of the first IDT, and a second dielectric layer is between the interleaved fingers of the second IDT. A thickness of the first dielectric layer is greater than a thickness of the second dielectric layer. The piezoelectric plate and the first and second IDTs are configured such that radio frequency signals applied to first and second IDTs excite primary shear acoustic modes in the respective diaphragms.

Filter device

An acoustic resonator has a substrate having a surface and a single-crystal piezoelectric plate, with a portion of the piezoelectric plate forming a diaphragm that spans a cavity in the substrate. An interdigital transducer (IDT) is formed on a surface of the single-crystal piezoelectric plate such that interleaved fingers of the IDT are disposed on the diaphragm. The ends of IDT interleaved fingers or inner surfaces of the opposing busbars have a curved shape. In some cases, gaps between ends of the interleaved fingers and opposing busbars have one of circular gap shapes or parabolic gap shapes. The cavity may be formed in an intermediate layer of the substrate.

Transversely-excited film bulk acoustic resonators with curved shaped ends of fingers or opposing busbars

Radio frequency filters are disclosed. A bandpass filter is discloses that includes one first bulk acoustic resonator on a first chip including a first piezoelectric layer having an LN-equivalent thickness less than or equal to 535 nm; a second bulk acoustic resonator on a second chip including a second piezoelectric layer having a thickness greater than the LN-equivalent thickness of the piezoelectric layer on the first chip; and a circuit card coupled to the first chip and the second chip and that electrically connects the first chip to the second chip.

Transversely-excited film bulk acoustic resonator filters with sub-resonators having different mark and pitch

An acoustic resonator device includes a portion of a piezoelectric plate is a diaphragm spanning a cavity in a substrate. A conductor pattern on a surface of the piezoelectric plate includes an interdigital transducer (IDT) with a first busbar, a second busbar, and a plurality of interleaved fingers extending alternately from the first and second busbars, first and second reflector elements proximate and parallel to a first finger of the interleaved fingers, and third and fourth reflector element proximate and parallel to a last finger of the interleaved fingers. Overlapping portions of the interleaved fingers and the first to fourth reflector elements are on the diaphragm. pr1 is a center-to-center distance of the first and second reflector elements and a center-to-center distance of the third and fourth reflector elements, p is a pitch of the interleaved fingers, and 1.1p≤pr1≤1.5p.

Low loss transversely-excited film bulk acoustic resonators and filters

An acoustic resonator device includes a diaphragm including a portion of the piezoelectric plate spanning a cavity in a substrate. A conductor pattern on a surface of the piezoelectric plate includes an interdigital transducer (IDT) with a first busbar, a second busbar, and a plurality of interleaved fingers, wherein the plurality of interleaved fingers extend alternately from the first and second busbars, overlapping portions of the plurality of interleaved fingers on the diaphragm. The conductor pattern also includes first and second reflector elements on the diaphragm proximate and parallel to a first finger of the plurality of interleaved fingers, and third and fourth reflector element on the diaphragm proximate and parallel to a last finger of the plurality of interleaved fingers.

Bandpass filters for a target communications band extending between a lower band edge and an upper band edge are disclosed. A bandpass filter includes one or more shunt resonators and one or more series resonators connected in a ladder filter circuit, wherein a relative difference between the anti-resonance and resonance frequencies of each acoustic resonator is greater than a fractional bandwidth of the target communications band. A first capacitor is connected in parallel with a first shunt resonator from the one or more shunt resonators, and a second capacitor connected in parallel with a first series resonator from the one or more series resonators.

Bandpass filters using transversely-excited film bulk acoustic resonators

Acoustic resonators and filters are disclosed. An acoustic resonator includes a substrate, a piezoelectric plate and an acoustic Bragg reflector between a surface of the substrate and a back surface of the piezoelectric plate. A conductor pattern on a front surface of the piezoelectric plate includes an interdigital transducer (IDT). The IDT includes a first busbar, a second busbar, and interleaved parallel fingers extending alternately from the first and second busbars. The fingers include a first finger and a last finger at opposing ends of the IDT. A first reflector element is proximate and parallel to the first finger and a second reflector element is proximate and parallel to the last finger. A distance pr between the first reflector element and the first finger and between the second reflector element and the last finger is greater than a pitch p of the IDT.

High Q solidly-mounted transversely-excited film bulk acoustic resonators

A 5 GHz Wi-Fi bandpass filter includes a ladder filter circuit with two or more shunt transversely-excited film bulk acoustic resonators (XBARs) and two or more series XBARs. Each of the two or more shunt XBARS includes a diaphragm having an LN-equivalent thickness greater than or equal to 360 nm, and each of the two or more series XBARS includes a diaphragm having an LN-equivalent thickness less than or equal to 375 nm.

Filter using transversely-excited film bulk acoustic resonators

Acoustic resonators, filters and methods of making resonators are disclosed. An acoustic resonator includes a substrate, a piezoelectric plate, and an acoustic Bragg reflector between a surface of the substrate and a back surface of the piezoelectric plate. An interdigital transducer (IDT) on a front surface of the piezoelectric plate includes first and second busbars and a plurality of interleaved fingers extending alternately from the first and second busbars. At least a portion of the first busbar contacts the substrate through an opening in the piezoelectric plate and acoustic Bragg reflector.

Solidly-mounted transversely-excited film bulk acoustic resonators with low thermal impedance

Acoustic filters, resonators and methods are disclosed. An acoustic filter device includes a substrate having a surface and a single-crystal piezoelectric plate having front and back surfaces, the back surface attached to the surface of the substrate except for a portion of the piezoelectric plate forming a diaphragm that spans a cavity in the substrate. An interdigital transducer is formed on the front surface of the piezoelectric plate with interleaved fingers of the IDT disposed on the diaphragm. At least a portion of a perimeter of the cavity is curved and at least one end zone of the perimeter of the cavity is round.

Transversely-excited film bulk acoustic resonator with a cavity having round end zones

An acoustic resonator device with low thermal impedance has a substrate and a single-crystal piezoelectric plate having a back surface attached to a top surface of the substrate via a bonding oxide (BOX) layer. An interdigital transducer (IDT) formed on the front surface of the plate has interleaved fingers disposed on the diaphragm, the overlapping distance of the interleaved fingers defining an aperture of the resonator device. Contact pads are formed at selected locations over the surface of the substrate to provide electrical connections between the IDT and contact bumps to be attached to the contact pads. The piezoelectric plate is removed from at least a portion of the surface area of the device beneath each of the contact pads to provide lower thermal resistance between the contact bumps and the substrate.

Transversely-excited film bulk acoustic resonator with reduced substrate to contact bump thermal resistance

Acoustic resonator devices and filters are disclosed. An acoustic resonator includes a substrate and a piezoelectric plate having front and back surfaces, the back surface attached to the substrate. A decoupling dielectric layer is on the front surface of the piezoelectric plate. An interdigital transducer (IDT) is formed over the decoupling dielectric layer such that interleaved fingers of the IDT are over a portion of the piezoelectric plate suspended across a cavity formed in the substrate. A thickness of the interleaved fingers is greater than or equal to 1.17 times a thickness of the piezoelectric plate and less than or equal to 1.7 times the thickness of the piezoelectric plate.

Growing community of inventors

Santa Barbara, CA, United States of America

Greg Dyer