# US 2019/0379348 A1 · Acoustic wave device with spinel layer and temperature compensation layer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0379348 A1 - Document ID: US20190379348A1 - Status: Published application - Kind: A1 - Application number: 16/430,078 - Filed: 2019-06-03 - Published: 2019-12-12 - Earliest claimed: 2018-06-11 - Assignees: Skyworks Solutions, Inc. - Applicants: Skyworks Solutions, Inc. - Inventors: Gong Bin Tang; Rei Goto; Hiroyuki Nakamura; Keiichi Maki - Web page: https://patentgrep.com/patent/US20190379348A1 ## CPC - H03F 3/195: in integrated circuits - H03H 9/02834: {of temperature influence (cut angles H03H9/02543)} - H03F 3/245: {with semiconductor devices only} - H03F 3/72: Gated amplifiers, i.e. amplifiers which are rendered operative or inoperative by means of a control signal - H03H 9/02559: {of lithium niobate or lithium-tantalate substrates} - H03H 9/02574: {of combined substrates, multilayered substrates, piezoelectrical layers on not-piezoelectrical substrate} - H03H 9/02866: {of bulk wave excitation and reflections} - H03H 9/14544: {Transducers of particular shape or position (weighting H03H9/14517)} - H03H 9/25: Constructional features of resonators using surface acoustic waves {(devices for manipulating acoustic surface waves in general G10K11/36)} - H03H 9/64: using surface acoustic waves - H03H 9/725: {Duplexers} - H04B 1/40: Circuits - H03F 3/24: of transmitter output stages - H03F 2200/111: the amplifier being a dual or triple band amplifier, e.g. 900 and 1800 MHz, e.g. switched or not switched, simultaneously or not - H03F 2200/294: the amplifier being a low noise amplifier [LNA] - H03F 2200/451: the amplifier being a radio frequency amplifier - H03F 2203/7209: the gated amplifier being switched from a first band to a second band - H03F: AMPLIFIERS - H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P) - H04B: TRANSMISSION ## Abstract An acoustic wave device that includes a spinel layer, a piezoelectric layer, a temperature compensating layer between the spinel layer and the piezoelectric layer and an interdigital transducer electrode on the piezoelectric layer is disclosed. The piezoelectric layer is disposed between the interdigital transducer electrode and the spinel layer. The acoustic wave device is configured to generate an acoustic wave having a wavelength of λ. The piezoelectric layer can have a thickness that is less than λ. In some embodiments, the spinel layer can be a polycrystalline spinel layer. ## Claims ### Claim 1 An acoustic wave device comprising: a piezoelectric layer; a spinel layer; a temperature compensating layer disposed between the piezoelectric layer and the spinel layer; and an interdigital transducer electrode on the piezoelectric layer, the piezoelectric layer being disposed between the temperature compensating layer and the interdigital transducer electrode. ### Claim 2 (depends on 1) The acoustic wave device of claim 1 wherein the spinel layer is a polycrystalline spinel layer. ### Claim 3 (depends on 1) The acoustic wave device of claim 1 wherein the spinel layer is a single crystalline spinel layer. ### Claim 4 (depends on 1) The acoustic wave device of claim 1 wherein the piezoelectric layer is a lithium tantalate layer. ### Claim 5 (depends on 1) The acoustic wave device of claim 1 wherein the piezoelectric layer is a lithium niobate layer. ### Claim 6 (depends on 1) The acoustic wave device of claim 1 wherein the acoustic wave device is a surface acoustic wave device configured to generate a surface acoustic wave. ### Claim 7 (depends on 1) The acoustic wave device of claim 1 wherein the acoustic wave device is configured to generate an acoustic wave having a wavelength of λ, and the piezoelectric layer has a thickness of less than λ. ### Claim 8 (depends on 1) The acoustic wave device of claim 1 wherein the temperature compensating layer includes silicon dioxide. ### Claim 9 (depends on 1) The acoustic wave device of claim 1 wherein the temperature compensating layer has a first surface and a second surface, the first surface being in physical contact with the spinel layer, and the second surface being in physical contact with the piezoelectric layer. ### Claim 10 (depends on 1) The acoustic wave device of claim 1 further comprising a substrate layer, the spinel layer being disposed between the substrate layer and the piezoelectric layer. ### Claim 11 (depends on 10) The acoustic wave device of claim 10 wherein the substrate layer is a silicon layer. ### Claim 12 (depends on 1) The acoustic wave device of claim 1 further comprising a high impedance layer disposed between the temperature compensating layer and the spinel layer, the high impedance layer having a higher acoustic impedance than the spinel layer. ### Claim 13 A radio frequency module comprising: an acoustic wave filter configured to filter a radio frequency signal, the acoustic wave filter including an acoustic wave device that includes a piezoelectric layer, an interdigital transducer electrode, a spinel layer, and a temperature compensating layer disposed between the piezoelectric layer and the spinel layer; and a package enclosing the acoustic wave filter. ### Claim 14 (depends on 13) The radio frequency module of claim 13 further comprising a second acoustic wave filter, the acoustic wave filter and the second acoustic wave filter being included in a duplexer. ### Claim 15 (depends on 13) The radio frequency module of claim 13 further comprising a radio frequency switch coupled to the acoustic wave filter, the radio frequency switch being enclosed within the package. ### Claim 16 (depends on 15) The radio frequency module of claim 15 further comprising a power amplifier enclosed within the package, the power amplifier configured to provide the radio frequency signal. ### Claim 17 (depends on 13) The radio frequency module of claim 13 wherein the acoustic wave device is a surface acoustic wave device configured to generate a surface acoustic wave having a wavelength of λ, and the piezoelectric layer has a thickness of less than λ. ### Claim 18 A wireless communication device comprising: an antenna; and a radio frequency front end in communication with the antenna, the radio frequency front end including an acoustic wave filter configured to filter a radio frequency signal, the acoustic wave filter including an acoustic wave device that includes a piezoelectric layer, an interdigital transducer electrode, a spinel layer, and a temperature compensating layer disposed between the piezoelectric layer and the spinel layer. ### Claim 19 (depends on 18) The wireless communication device of claim 18 further comprising a second acoustic wave filter, the acoustic wave filter and the second acoustic wave filter being included in a duplexer. ### Claim 20 (depends on 18) The wireless communication device of claim 18 wherein the acoustic wave filter is a surface acoustic wave filter.