Abstract: The depth of focus in the elevation plane of an acoustic ultrasound transducer is extended. The ultrasound transducer comprises an acoustic element, said element having a substantially uniform frequency amplitude characteristic across its spatial extent and transmitting an ultrasound beam when excited, an acoustic lens positioned in front of said element, said lens having a cross sectional profile comprising (1) a curved portion with a curved front surface and a back surface facing said transducer element, said curved lens portion providing a focal point at a first focal range, and (2) a pair of linear portions with linear front surfaces and back surfaces facing said transducer element, said linear portions positioned on either side of said curved portion, and said linear portions providing continuous focusing at imaging ranges after said first focal depth of said curved portion.