Research Article
An Analytical Model for Bandwidth Enhancement of Air-Coupled Unsealed Helmholtz Structural CMUTs
Table 4
3-dB fractional bandwidth and SPL-bandwidth product of the Half case as shown in Figure
9.
| | Hole radius [µm] | a=10 | a=20 | a=30 | a=40 | a=50 | no hole |
| | fh [kHz] | 184.6 | 277.1 | 353.1 | 422.6 | 489.6 | =334.9 | | Separation between fp and fh [kHz] | 150.3 | 57.8 | 18.2 | 87.7 | 154.7 | | | 3-dB fractional bandwidth | 5.4% | 10.9% | 24.0% | 14.7% | 6.5% | 1.3% | | SPL-bandwidth product | 2.67 | 5.29 | 11.06 | 6.08 | 2.62 | 0.67 |
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