TABLE II.
−20-dB Effective Width W, Radius R, and Peripheral Energy Ratio (PER) of Receive Focuses for Apertures Partitioned With Different Element Pitches.
| Pitch (mm) | WElev (mm) | WArray (mm) | Reff (mm) | PER |
|---|---|---|---|---|
| Elevation pitch | ||||
| Unc (0.6 × 0.6) | 9.6 | 6.3 | 3.9 | 2.99 |
| Ideal (0.6 × 0.6) | 2.0 | 1.9 | 1.0 | 0.02 |
| Comp (0.6 × 0.6) | 2.3 | 2.2 | 1.1 | 0.12 |
| Comp (1.8 × 0.6) | 2.4 | 2.2 | 1.1 | 0.14 |
| Comp (3.0 × 0.6) | 2.4 | 2.2 | 1.1 | 0.19 |
| Comp (4.2 × 0.6) | 2.4 | 2.1 | 1.1 | 0.26 |
| Comp (5.4 × 0.6) | 6.4 | 2.1 | 1.8 | 0.36 |
| Square pitch | ||||
| Unc (0.6 × 0.6) | 9.6 | 6.3 | 3.9 | 2.99 |
| Ideal (0.6 × 0.6) | 2.0 | 1.9 | 1.0 | 0.02 |
| Comp (0.6 × 0.6) | 2.3 | 2.2 | 1.1 | 0.12 |
| Comp (1.8 × 1.8) | 2.4 | 2.3 | 1.2 | 0.16 |
| Comp (3.0 × 3.0) | 2.4 | 2.3 | 1.2 | 0.25 |
| Comp (4.2 × 4.2) | 2.5 | 2.2 | 1.2 | 0.36 |
| Comp (5.4 × 5.4) | 6.9 | 2.1 | 1.9 | 0.55 |
Unc = uncompensated; Comp = compensated.