Apparatus with ultrasonic fingerprint sensor and one or more resonators, and related systems and methods
US11798308B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 17, 2021 |
| Grant date | Oct 24, 2023 |
| Priority date | — |
| Expiry date | Sep 17, 2041 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V40/1329
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Some disclosed implementations include an ultrasonic sensor stack and an acoustic resonator. The acoustic resonator may be configured to enhance ultrasonic waves transmitted by the ultrasonic sensor stack in an ultrasonic frequency range that is suitable for ultrasonic fingerprint sensors. In some examples, the acoustic resonator may include one or more low-impedance layers residing between a first higher-impedance layer and a second higher-impedance layer. Each of the one or more low-impedance layers may have a lower acoustic impedance than an acoustic impedance of the first higher-impedance layer or an acoustic impedance of the second higher-impedance layer. At least one low-impedance layer may have a thickness corresponding to a multiple of a half wavelength at a peak frequency of the acoustic resonator. The peak frequency may be within a frequency range from 1 MHz. to 20 MHz.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.