Abstract: An acoustic resonator device is provided that includes a substrate having a surface; a piezoelectric layer attached to the surface of the substrate via an intermediate layer, the piezoelectric layer including a portion that is over a cavity in the intermediate layer; a conductor pattern including an interdigital transducer (IDT) on a surface of the piezoelectric layer and having interleaved fingers on the piezoelectric layer; a dielectric layer at least between the interleaved fingers of the IDT; and a dielectric cover over the IDT and the piezoelectric layer, the dielectric cover including a bottom surface, wherein at least a portion of the dielectric cover is attached to a portion of the conductor pattern, wherein the conductor pattern includes at least two metal layers including a first metal layer of the interleaved fingers of the IDT and a second metal layer attached to the dielectric cover.

Abstract: A bandpass filter is provided that includes series acoustic resonators and shunt acoustic resonators. The shunt acoustic resonators include a first transversely-excited film bulk acoustic resonators (XBAR) that includes a diaphragm comprising a portion of a piezoelectric layer that is over a cavity of the first XBAR and a first interdigital transducer (IDT) on a surface of the piezoelectric layer. The first XBAR is connected between (i) a node directly between a first series acoustic resonator of the plurality of series acoustic resonators and the input port, and (ii) a ground of the bandpass filter. The series and shunt acoustic resonators include one or more solidly-mounted XBARs that includes a portion of a second piezoelectric layer that is solidly mounted over a substrate with a Bragg reflector disposed therebetween.

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.

Abstract: An acoustic resonator device includes a substrate having a surface and a single-crystal piezoelectric plate bonded to the substrate surface. A portion of the piezoelectric plate forms a diaphragm that spans a cavity. A conductor pattern including an interdigital transducer (IDT) formed on a surface of the single-crystal piezoelectric plate such that interleaved fingers of the IDT are disposed on the diaphragm. A dielectric cover is disposed over the IDT and the plate, and the dielectric cover forms an air gap above the IDT and the plate.

Abstract: Radio frequency filters. A radio frequency filter includes a substrate attached to a piezoelectric plate, portions of the piezoelectric plate forming a plurality of diaphragms spanning respective cavities in the substrate. A conductor pattern formed on the piezoelectric plate includes a plurality of interdigital transducers (IDTs) of a respective plurality of resonators, interleaved fingers of each IDT disposed on a respective diaphragm of the plurality of diaphragms. The conductor pattern connects the plurality of resonators in a matrix filter circuit including a first sub-filter and a second sub-filter, each sub-filter comprising two or more resonators from the plurality of resonators.

Abstract: A bandpass filter is provided that includes a ladder filter circuit having series and shunt transversely-excited film bulk acoustic resonators (XBARs). The series XBAR includes a lithium niobate piezoelectric layer; and a front side dielectric layer that comprises a silicon oxide between interleaved fingers of an interdigital transducer of the series XBAR disposed on the lithium niobate piezoelectric layer of the series XBAR. Similarly, the shunt XBAR includes a lithium niobate piezoelectric layer; and a front side dielectric layer that comprises a silicon oxide between interleaved fingers of an interdigital transducer of the shunt XBAR disposed on the lithium niobate piezoelectric layer of the shunt XBAR.

Abstract: A 6 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 310 nm, and each of the two or more series XBARS includes a diaphragm having an LN-equivalent thickness less than or equal to 305 nm.

Abstract: Acoustic filters are disclosed. A bandpass filter has a passband between a lower band edge and an upper band edge. The bandpass filter includes a plurality of transversely-excited film bulk acoustic resonators (XBARs) connected in a ladder filter circuit. The plurality of XBARs includes at least one lithium tantalate XBAR and at least one lithium niobate XBAR.

Abstract: Filter devices and methods are disclosed. A single-crystal piezoelectric plate is attached to substrate, portions of the piezoelectric plate forming a plurality of diaphragms spanning respective cavities in the substrate. A conductor pattern formed on the piezoelectric plate defines a low band filter including low band shunt resonators and low band series resonators and a high band filter including high band shunt resonators and high band series resonators. Interleaved fingers of interdigital transducers (IDTs) of the low band shunt resonators are disposed on respective diaphragms having a first thickness, interleaved fingers of IDTs of the high band series resonators are disposed on respective diaphragms having a second thickness less than the first thickness, and interleaved fingers of IDTs of the low band series resonators and the high band shunt resonators are disposed on respective diaphragms having thicknesses intermediate the first thickness and the second thickness.

Abstract: 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.

Abstract: A bandpass filter is provided that includes a ladder filter circuit with at least one shunt transversely-excited film bulk acoustic resonators (XBAR) and at least one series XBAR. Each of the XBARs includes a diaphragm having an LN-equivalent thickness greater than or equal to 360 nm, and each of the XBARs includes a diaphragm having an LN-equivalent thickness less than or equal to 375 nm.

Abstract: Communications devices are disclosed. A communications device includes an unlicensed national information infrastructure frequency range 1 (U-NII-1) to U-NII-2A transceiver coupled to a first antenna though a U-NII-1 to U-NII-2A coexistence filter, and a U-NII-2C to U-NII-8 transceiver coupled to a second antenna though a U-NII-2C to U-NII-8 coexistence filter.

Abstract: An acoustic filter device includes a transversely-excited film bulk acoustic resonator (XBAR) including a plurality of sub-resonators, and conductors connecting the plurality of sub-resonators in series between a first node and a second node. At least one of the conductors connects two of the plurality of sub-resonators and has a shape that minimizes an area of the at least one conductor.

Abstract: Tiled filters are disclosed. A filter includes an n×m array of sub-filters, where n is a number of sub-filters in parallel and m is a number of sub-filters in series. n and m are non-zero positive integers and at least one of n and m is greater than one. All of the nm sub-filters are bandpass filters with substantially the same passbands.

Abstract: A radio frequency filter includes at least a first sub-filter and a second sub-filter connected in parallel between a first port and a second port. Each of the sub-filters has a piezoelectric plate having front and back surfaces, the back surface attached to a substrate, and portions of the piezoelectric plate forming diaphragms spanning respective cavities in the substrate. A conductor pattern is formed on the front surface of the plate, the conductor pattern includes interdigital transducers (IDTs) of a respective plurality of resonators, with interleaved fingers of each IDT disposed on a respective diaphragm of the plurality of diaphragms. A thickness of the portions of the piezoelectric plate of the first sub-filter is different from a thickness of the portions of the piezoelectric plate of the second sub-filter.

Abstract: Acoustic filter devices and methods of making filter devices. An acoustic filter device includes a transversely-excited film bulk acoustic resonator (XBAR) including a plurality of sub-resonators and conductors to connect the plurality of sub-resonators in parallel between a first node and a second node. The conductors are configured such that a path length from the first node to the second node is effectively the same through each of the plurality of sub-resonators.

Abstract: A filter is provided that includes resonators connected in series between first and second ports. Each of the resonators includes a piezoelectric layer; and an interdigital transducer (IDT) having a plurality of interleaved fingers at a surface of the piezoelectric layer. The piezoelectric layer and the IDT are configured such that a radio frequency signal applied to the IDT excites a primary shear acoustic mode in the piezoelectric layer. The filter includes a capacitor connected between ground and a node between the first bulk acoustic resonator and the second bulk acoustic resonator.

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 bonded to 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 to function at 15 GHz.

Abstract: Acoustic filters are disclosed. A bandpass filter has a passband between a lower band edge and an upper band edge. The bandpass filter includes a plurality of transversely-excited film bulk acoustic resonators (XBARs) connected in a ladder filter circuit. The plurality of XBARs includes at least one lithium tantalate (LT) XBAR and at least one lithium niobate XBAR. Each of the at least one LT XBAR includes an LT piezoelectric plate with Euler angles (0°, ?, 0°), where ? is greater than zero and less than or equal to 40 degrees.

Abstract: There are disclosed acoustic diplexers and radios incorporating the acoustic diplexers. A diplexer includes common port, a low band port, a high band port, n low band sub-filters, and n high band sub-filters, where n is an integer greater than one. Each low band sub-filter has a first sub-filter port connected to the common port and a second sub-filter port connected to the low band port. Each high band sub-filter has a first sub-filter port connected to the common port and a second sub-filter port connected to the high band port. A first acoustic resonator is connected from the common port to ground and a second acoustic resonator is connected from the low band port to ground. The first and second acoustic resonators are configured to create respective transmission zeros adjacent to a lower edge of a passband of the diplexer.