Table 2.

Transducers analyzed and summary of results.

			Transducer configuration
			# 1	# 2	# 3
Physical configuration	Radiating surface intensity (W∕cm2)		2.0	2.0	2.0
	Radius of curvature (cm)		13	13	13
	Aperture diameter (cm)		15.4	10.3	15.4
	Frequency (MHz)		1.0	1.0	0.5
	Number of elements		256	256	256
	Element radius (cm)		0.33	0.22	0.33
	Element location		Random	Random	Random
	Average interelement spacing		6λ	3λ	3λ
Beam characteristics	Near-field deposition ratio γ	Unsteered	0.03	0.11	0.08
		Steered 1 cm transverse	0.04	0.08	0.07
		Steered 1 cm axial	0.07	0.11	0.08
	Maximum Q at focus ( × 108 W∕m3)	Unsteered	1.15	0.25	0.2
		Steered transverse	0.66	0.18	0.16
		Steered axial	0.88	0.19	0.16
	focal size (transverse × axial) (mm)		1.6 × 7.2	2.4 × 15.3	3.3 × 14.5