A synthetic receive aperture technique is explored for cost-effective ultrasound scanners with high frame rates and beam density. The technique provides ultrasound volumetric imaging where beam count is very large with 2-D transducer arrays using subaperture processing. For every beam Ene, transmit beam is performed with a small subaperture whereas the reflected echo signals are received from non-overlapping subapertures. For every transmit-receive subaperture combination, a small number of beams are acquired and then the number of beam lines is increased through beam space interpolation. A 2-D linear filter with a different spatial frequency band for each subaperture is employed as the interpolation filter. Performance of the technique is analyzed through simulations. The technique reduces the number of firings and therefore allows real-time imaging with very low susceptibility to motion artifacts.