Abstract
The transducer resonance frequency is a key parameter for the field of ultrasound. The resonance frequency in vacuum is well understood, and an analytical expression for the center frequency in immersion was derived by Lamb in 1920 [1], however this expression has limited validity. Importantly, the model fails to cover plate aspect ratios needed by imaging requirements and met by recently fabricated medical Capacitive Micromachined Ultrasonic Transducers (CMUTs). Based on the equation of motion a new expression for the resonance frequency in immersion is derived. The influence of the immersion medium is included via the radiation impedance, which is approximated using the well-known Taylor expansion, yielding results similar to Lamb's. For precision at smaller aspect ratios, this work proposes using the Padé approximant instead. Comparing the frequency ratio to FEM simulations, the Padé approximant shows a fourfold reduction in error from 12.0% to 3.0%.
| Original language | English |
|---|---|
| Title of host publication | Proceedings of 2022 IEEE International Ultrasonics Symposium (IUS) |
| Number of pages | 4 |
| Publisher | IEEE |
| Publication date | 2022 |
| ISBN (Print) | 978-1-6654-7813-7 |
| ISBN (Electronic) | 978-1-6654-6657-8 |
| DOIs | |
| Publication status | Published - 2022 |
| Event | 2022 IEEE International Ultrasonics Symposium - Venice, Italy Duration: 10 Oct 2022 → 13 Oct 2022 |
Conference
| Conference | 2022 IEEE International Ultrasonics Symposium |
|---|---|
| Country/Territory | Italy |
| City | Venice |
| Period | 10/10/2022 → 13/10/2022 |