# US 11,909,378 B2 · Acoustic wave device with velocity adjustment layer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,909,378 B2 - Document ID: US11909378B2 - Status: Granted - Kind: B2 - Application number: 17/099,603 - Filed: 2020-11-16 - Published: 2021-05-27 - Granted: 2024-02-20 - Earliest claimed: 2019-11-21 - Assignees: Skyworks Solutions, Inc. - Applicants: Skyworks Solutions, Inc. - Inventors: Joshua James Caron; Rei Goto; Benjamin Paul Abbott; Hiroyuki Nakamura - Web page: https://patentgrep.com/patent/US11909378B2 ## CPC - H03H 9/02685: {Grating lines having particular arrangements} - H03F 3/195: in integrated circuits - H03F 3/245: {with semiconductor devices only} - H03H 9/02574: {of combined substrates, multilayered substrates, piezoelectrical layers on not-piezoelectrical substrate} - H03H 9/02834: {of temperature influence (cut angles H03H9/02543)} - H03H 9/02842: {of reflections (H03H9/6406 takes precedence)} - H03H 9/145: for networks using surface acoustic waves - H03H 9/25: Constructional features of resonators using surface acoustic waves {(devices for manipulating acoustic surface waves in general G10K11/36)} - H03H 9/6406: {Filters characterised by a particular frequency characteristic} - H03H 9/6436: {having one acoustic track only} - H03H 9/6483: {Ladder SAW filters} - H04B 1/40: Circuits - 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 2200/451: the amplifier being a radio frequency amplifier - H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P) - H03F: AMPLIFIERS - H04B: TRANSMISSION ## Abstract Aspects of this disclosure relate to a surface acoustic wave device that includes a first reflector over a piezoelectric layer, a second reflector over the piezoelectric layer, and an interdigital transducer electrode structure over the piezoelectric layer and positioned between the first reflector and the second reflector. The surface acoustic wave device includes a velocity adjustment layer arranged to adjust acoustic velocity in a region of the surface acoustic wave device. The velocity adjustment layer can be a high speed layer or a low speed layer. ## Claims ### Claim 1 A surface acoustic wave device comprising: a piezoelectric layer; a first reflector over the piezoelectric layer; a second reflector over the piezoelectric layer; an interdigital transducer electrode structure over the piezoelectric layer and positioned between the first reflector and the second reflector, the interdigital transducer electrode structure having a first side closer to the first reflector and a second side closer to the second reflector; and a high speed layer positioned over at least a portion between the first side and the first reflector such that an acoustic wave propagation velocity in a fast region overlapping the high speed layer is greater than an acoustic wave propagation velocity in a region between the first side and the second side. ### Claim 2 (depends on 1) The surface acoustic wave device of claim 1 further comprising a low speed layer positioned over the first reflector such that an acoustic wave propagation velocity in a slow region over the first reflector is slower than in the fast region overlapping the high speed layer and the region between the first side and the second side. ### Claim 3 (depends on 2) The surface acoustic wave device of claim 2 wherein the low speed layer and the first reflector are spaced apart by a temperature compensation layer. ### Claim 4 (depends on 2) The surface acoustic wave device of claim 2 wherein a portion of the high speed layer and a portion of the low speed layer vertically overlap. ### Claim 5 (depends on 1) The surface acoustic wave device of claim 1 wherein the surface acoustic wave device is arranged as a multi-mode surface acoustic wave filter. ### Claim 6 (depends on 5) The surface acoustic wave device of claim 5 wherein the interdigital transducer electrode structure has a pitch variation of less than 10 percent. ### Claim 7 (depends on 1) The surface acoustic wave device of claim 1 wherein the surface acoustic wave device is a surface acoustic wave resonator. ### Claim 8 A surface acoustic wave device comprising: a piezoelectric layer; a first reflector over the piezoelectric layer; a second reflector over the piezoelectric layer; an interdigital transducer electrode structure over the piezoelectric layer and positioned between the first reflector and the second reflector, the interdigital transducer electrode structure having a first side closer to the first reflector and a second side closer to the second reflector; and a low speed layer positioned in a slow region over the first reflector such that an acoustic wave propagation velocity in the slow region is slower than an acoustic wave propagation velocity in a region between the first side and the second side. ### Claim 9 (depends on 8) The surface acoustic wave device of claim 8 further comprising a temperature compensation layer over the interdigital transducer electrode structure, the first reflector, and the second reflector. ### Claim 10 (depends on 9) The surface acoustic wave device of claim 9 wherein the low speed layer and the first reflector are spaced apart by the temperature compensation layer. ### Claim 11 (depends on 8) The surface acoustic wave device of claim 8 wherein the surface acoustic wave device is arranged as a multi-mode surface acoustic wave filter. ### Claim 12 (depends on 11) The surface acoustic wave device of claim 11 wherein the interdigital transducer electrode structure has a pitch variation of less than 10 percent. ### Claim 13 (depends on 8) The surface acoustic wave device of claim 8 wherein the surface acoustic wave device is a surface acoustic wave resonator. ### Claim 14 (depends on 8) A radio frequency module comprising: a filter including a surface acoustic wave device of claim 8; and a radio frequency circuit element coupled to the filter, the filter and the radio frequency circuit element being enclosed within a common module package. ### Claim 15 (depends on 14) The radio frequency module of claim 14 wherein the radio frequency circuit element is a radio frequency amplifier arranged to amplify a radio frequency signal. ### Claim 16 (depends on 14) The radio frequency module of claim 14 wherein the radio frequency circuit element is a switch configured to selectively couple the filter to a port of the radio frequency module. ### Claim 17 A wireless communication device comprising: a filter including a surface acoustic wave device having a piezoelectric layer, a first reflector over the piezoelectric layer, a second reflector over the piezoelectric layer, an interdigital transducer electrode structure having a first side closer to the first reflector and a second side closer to the second reflector over the piezoelectric layer and positioned between the first reflector and the second reflector, and a high speed layer positioned over at least a portion between the first side and the first reflector such that an acoustic wave propagation velocity in a fast region overlapping the high speed layer is greater than an acoustic wave propagation velocity in a region between the first side and the second side; an antenna operatively coupled to the filter; a radio frequency amplifier operatively coupled to the filter and configured to amplify a radio frequency signal; and a transceiver in communication with the radio frequency amplifier. ### Claim 18 (depends on 17) The wireless communication device of claim 17 further comprising a baseband processor in communication with the transceiver. ### Claim 19 (depends on 17) The wireless communication device of claim 17 wherein the filter is included in a radio frequency front end. ### Claim 20 (depends on 17) The wireless communication device of claim 17 wherein the filter is included in a diversity receive module.