Abstract: A filter device has a first piezoelectric plate spanning a first and second cavity of a substrate. A first and second interdigital transducer (IDT) are on a front surface of the first piezoelectric plate over the first and second cavity. A dielectric layer is formed on the first piezoelectric plate and covers the first IDT and second IDT. A second piezoelectric plate is bonded to a front surface of the dielectric layer over the first cavity and the second cavity. A second dielectric layer is formed on a front surface of the second piezoelectric plate over the first cavity but not over the second cavity. The thickness of the dielectric layer, the first piezoelectric plate and the second piezoelectric plate can be selected to tune a shunt resonator over the first cavity and a series resonator over the second cavity.

Abstract: Acoustic resonator devices and filters are disclosed. An acoustic resonator includes a substrate and a single-crystal piezoelectric plate. A back surface of a supported portion of the piezoelectric plate is attached to a surface of the substrate. A portion of the piezoelectric plate forms a diaphragm that spans a cavity in the substrate. An interdigital transducer (IDT) is formed on a front surface of the piezoelectric plate. The IDT includes first and second busbars, and interleaved fingers extending alternately from the first and second busbars. Overlapping portions of the interleaved fingers are disposed on the diaphragm. At least portions of both the first and second busbars are disposed on the supported portion of the piezoelectric plate.

Abstract: There are disclosed matrix filters having an input port and sub-filters connected between the input port and respective output ports. Each of the sub-filters includes a ladder circuit with n transversely-excited film bulk acoustic resonator (XBAR) series elements and n?1 capacitor shunt elements, where n, the order of the sub-filter, is an integer greater than 2. Each sub-filter further has a first switch in parallel with a first capacitor shunt element and a second switch in parallel with a last capacitor shunt element.

Abstract: An acoustic resonator is fabricated by bonding a first piezoelectric plate to a substrate and spans locations for a first and second cavity in the substrate. A top surface of the first piezoelectric plate is planarized to a first thickness. A bonding layer is formed on the first piezoelectric plate and spans the first and second cavity locations. A second piezoelectric plate is bonded to the bonding layer and spans the first and second cavity locations. A portion of the second piezoelectric plate spanning the second cavity location is etched away to form a first membrane over the first cavity location and a second membrane over the second cavity location. Interdigital transducers are formed on the first and second membranes over the first and second cavity location to form a first and second resonator on the same die.

Abstract: Acoustic resonator devices and acoustic filter devices. An acoustic resonator includes a piezoelectric plate having front and back surfaces, a portion of the piezoelectric plate forming a diaphragm, and a conductor pattern on the front surface, the conductor pattern comprising an interdigital transducer (IDT), interleaved fingers of the IDT on the diaphragm. A ratio of a mark of the interleaved fingers to a pitch of the interleaved fingers is greater than or equal to 0.12 and less than or equal to 0.3. A thickness of the interleaved fingers is greater than or equal to 0.85 times a thickness of the piezoelectric plate and less than or equal to 2.5 times the thickness of the piezoelectric plate.

Abstract: An acoustic wave device is provided that includes a piezoelectric layer and first and second resonators. The first resonator includes a first functional electrode and a first dielectric film on the piezoelectric layer. The second resonator includes a second functional electrode and a second dielectric film on the piezoelectric layer. The piezoelectric layer includes first and second resonator portions respectively including portions of the first and second resonators. Moreover, a resonant frequency of the first resonator is lower than that of the second resonator. A thickness of the first resonator portion is greater than that of the second resonator portion, and ts1/tp1?ts2/tp2 is satisfied, where tp1, tp2, ts1, and ts2 are respectively thicknesses of the first and second resonator portions and the first and second dielectric films.

Abstract: There is disclosed acoustic resonators and filter devices. An acoustic resonator device includes a piezoelectric plate, a portion of the piezoelectric plate forming a diaphragm, a thickness of the piezoelectric plate is greater than or equal to 300 nm and less than or equal to 500 nm, and an interdigital transducer (IDT) with interleaved fingers of the IDT on the diaphragm. The piezoelectric plate and the IDT are configured such that a radio frequency signal applied to the IDT excites a primary shear acoustic mode in the diaphragm.

Abstract: Acoustic resonators and filter devices. An acoustic resonator includes a piezoelectric plate having front and back surfaces, a portion of the piezoelectric plate forming a diaphragm, and a conductor pattern on the front surface, the conductor pattern including an interdigital transducer (IDT), interleaved fingers of the IDT on the diaphragm. A ratio of a mark of the interleaved fingers to a pitch of the interleaved fingers is greater than or equal to 0.12 and less than or equal to 0.3. The pitch of the interleaved fingers is greater than or equal to 6 times a thickness of the piezoelectric plate and less than or equal to 12.5 times the thickness of the piezoelectric plate.

Abstract: There are disclosed matrix filters having an antenna port, receive ports and transmit ports. A receive matrix filter is coupled between each receive port and the antenna port; an a transmit matrix filter is coupled between the antenna port and each transmit port. An impedance at the receive port is matched to an input impedance of a low noise amplifier (LNA), an impedance at the transmit port is match to an output impedance of a power amplifier (PA), and an impedance at the antenna port is match an impedance of an antenna.

Abstract: Band N77 bandpass filters include a first plurality of transversely-excited film bulk acoustic resonators (XBARs) on a first chip comprising a first rotated YX-cut lithium niobate piezoelectric plate having a thickness less than or equal to 535 nm, and a second plurality of XBARs on a second chip comprising a second rotated YX-cut lithium niobate piezoelectric plate having a thickness greater than or equal to 556 nm. A circuit card is coupled to the first chip and the second chip. The circuit card includes conductors for making electrical connections between the first chip and the second chip.

Abstract: Acoustic resonators are disclosed. An acoustic resonator includes a substrate having a surface and a single-crystal piezoelectric plate having front and back surfaces. The back surface is attached to the surface of the substrate except for a portion of the piezoelectric plate forming a diaphragm spanning a cavity in the substrate. An interdigital transducer (IDT) is formed on the front surface of the piezoelectric plate. The IDT includes: a first busbar and a second busbar disposed on respective portions of the piezoelectric plate other than the diaphragm; a first set of elongate fingers extending from the first bus bar onto the diaphragm; and a second set of elongate fingers extending from the second bus bar onto the diaphragm, the second set of elongate fingers interleaved with the first set of elongate fingers.

Abstract: An acoustic resonator device, filter devices, and methods of making the same. An acoustic resonator device includes a substrate having a surface and a single-crystal piezoelectric plate having front and back surfaces, where the back surface is 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. The device further includes an interdigital transducer formed on the front surface of the piezoelectric plate, where interleaved fingers of the IDT disposed on the diaphragm are configured such that a radio frequency signal applied to the IDT excites a primary shear acoustic mode in the diaphragm. The interleaved fingers include a first layer adjacent the diaphragm and a second layer over the first layer, the second layer having a narrower width than the first layer.

Abstract: There are disclosed matrix filters having an input port and sub-filters connected between the input port and respective output ports. Each of the sub-filters includes a ladder circuit with n transversely-excited film bulk acoustic resonator (XBAR) series elements and n?1 capacitor shunt elements, where n, the order of the sub-filter, is an integer greater than 2. The sub-filters having noncontiguous passbands.

Abstract: There is disclosed acoustic resonators and filter devices. An acoustic resonator 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 (IDT) is formed on the front surface of the single-crystal piezoelectric plate such that interleaved fingers of the IDT are disposed on the diaphragm. The piezoelectric plate and the IDT are configured such that a radio frequency signal applied to the IDT excites a primary shear acoustic mode in the diaphragm. The interleaved fingers comprise a first layer adjacent the diaphragm and a second layer over the first layer opposite the diaphragm, the second layer having a greater width than the first layer.

Abstract: A filter device has a first piezoelectric plate spanning a first and second cavity of a substrate. A first and second interdigital transducer (IDT) are on a front surface of the first piezoelectric plate over the first and second cavity. A dielectric layer is formed on the first piezoelectric plate and covers the first IDT and second IDT. A second piezoelectric plate is bonded to a front surface of the dielectric layer over the first cavity and the second cavity. A second dielectric layer is formed on a front surface of the second piezoelectric plate over the first cavity but not over the second cavity. The thickness of the dielectric layer, the first piezoelectric plate and the second piezoelectric plate can be selected to tune a shunt resonator over the first cavity and a series resonator over the second cavity.

Abstract: Resonator devices are disclosed. An acoustic resonator device includes a piezoelectric plate having front and back surfaces, an acoustic Bragg reflector on the back surface, and an interdigital transducer (IDT) on the front surface. The acoustic Bragg reflector reflects a primary shear acoustic mode excited by the IDT in the piezoelectric plate over a frequency range including a resonance frequency and an anti-resonance frequency of the acoustic resonator device.

Abstract: An acoustic filter includes a piezoelectric plate on a substrate. Portions of the piezoelectric plate form one or more diaphragms, each diaphragm spanning a respective cavity in the substrate. A conductor pattern on a front surface of the piezoelectric plate includes interdigital transducers (IDTs) of acoustic resonators including a shunt resonator and a series resonator. Interleaved fingers of each IDT are on a diaphragm of the one or more diaphragms. A first dielectric layer with a first thickness is between the fingers of the IDT of the shunt resonator, and a second dielectric layer with a second thickness less than the first thickness is between the fingers of the IDT of the series resonator. The piezoelectric plate and the IDTs are configured such that radio frequency signals applied to the IDTs excite respective primary shear acoustic modes within the diaphragms.

Abstract: Acoustic resonators and filter devices. An acoustic resonator includes a substrate having a surface and a single-crystal piezoelectric plate having front and back surfaces. The back surface is attached to the surface of the substrate except for a portion of the piezoelectric plate forming a diaphragm spanning a cavity in the substrate. A conductor pattern formed is formed on the front surface of the piezoelectric plate, including an interdigital transducer (IDT) with interleaved fingers of the IDT on the diaphragm. The substrate and the piezoelectric plate are the same material.

Abstract: Acoustic resonators and filter devices. An acoustic resonator includes a piezoelectric plate having front and back surfaces, a portion of the piezoelectric plate forming a diaphragm, and a conductor pattern on the front surface, the conductor pattern including an interdigital transducer (IDT), fingers of the IDT on the diaphragm. A thickness of the interleaved fingers is greater than or equal to 0.85 times a thickness of the piezoelectric plate and less than or equal to 2.5 times the thickness of the piezoelectric plate. The IDT comprises a first portion having a first pitch and a first mark and a second portion having a second pitch and a second mark not equal to the first pitch and first mark.

Abstract: 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.