TABLE III.
−20-dB Effective Width W, Radius R, and Peripheral Energy Ratio (PER) of Transmit Focuses for Apertures Partitioned With Different Element Pitches.
| Pitch (mm) | WElev (mm) | WArray (mm) | Reff (mm) | PER |
|---|---|---|---|---|
| Elevation pitch | ||||
| Unc (0.6 × 0.6) | 6.3 | 6.3 | 3.2 | 1.98 |
| Ideal (0.6 × 0.6) | 1.7 | 1.6 | 0.8 | 0.11 |
| Comp (0.6 × 0.6) | 1.7 | 1.6 | 0.8 | 0.13 |
| Comp (1.8 × 0.6) | 1.7 | 1.6 | 0.8 | 0.14 |
| Comp (3.0 × 0.6) | 1.7 | 1.6 | 0.8 | 0.17 |
| Comp (4.2 × 0.6) | 1.7 | 1.6 | 0.8 | 0.19 |
| Comp (5.4 × 0.6) | 1.6 | 1.6 | 0.8 | 0.38 |
| Square pitch | ||||
| Unc (0.6 × 0.6) | 6.3 | 6.3 | 3.2 | 1.98 |
| Ideal (0.6 × 0.6) | 1.7 | 1.6 | 0.8 | 0.11 |
| Comp (0.6 × 0.6) | 1.7 | 1.6 | 0.8 | 0.13 |
| Comp (1.8 × 1.8) | 1.7 | 1.7 | 0.9 | 0.15 |
| Comp (3.0 × 3.0) | 2.2 | 1.7 | 1.0 | 0.23 |
| Comp (4.2 × 4.2) | 2 2 | 1.7 | 1.0 | 0.24 |
| Comp (5.4 × 5.4) | 2.1 | 2.8 | 1.2 | 0.58 |
Unc = uncompensated; Comp = compensated.