A method for controlling the aperture of an array transducer of an ultrasound probe, wherein the array transducer comprises a two dimensional array of transducer elements, the transducer elements of the array being coupled to a microbeamformer in the probe which performs at least partial beamforming of received echo signals, the method comprising: configuring the aperture of the array into patches of different sizes, each patch comprising a group of transducer elements coupled to the microbeamformer; receiving echoes from a shallow depth of field with an aperture of one or more patches of a first, relatively small size; receiving echoes from a deeper depth of field by growing the aperture to add patches of a larger size than the first, relatively small size, characterized in that the configuring further comprises either (i) configuring patches of a uniform size in the elevation dimension and different sizes in the azimuth dimension, such that a smallest patch is positioned in a center of the aperture in the azimuth dimension with patches of progressively increasing size extending on either side of that smallest patch to the azimuth limits of the aperture on either side of that smallest patch, or (ii) configuring patches of a uniform size in the azimuth dimension and different sizes in the elevation dimension, such that a smallest patch is positioned in a center of the aperture in the elevation dimension with patches of progressively increasing size extending on either side of that smallest patch to the elevation limits of the aperture on either side of that smallest patch. configuring the aperture of the array into patches of different sizes, each patch comprising a group of transducer elements coupled to the microbeamformer; receiving echoes from a shallow depth of field with an aperture of one or more patches of a first, relatively small size; receiving echoes from a deeper depth of field by growing the aperture to add patches of a larger size than the first, relatively small size, characterized in that the configuring further comprises either (i) configuring patches of a uniform size in the elevation dimension and different sizes in the azimuth dimension, such that a smallest patch is positioned in a center of the aperture in the azimuth dimension with patches of progressively increasing size extending on either side of that smallest patch to the azimuth limits of the aperture on either side of that smallest patch, or (ii) configuring patches of a uniform size in the azimuth dimension and different sizes in the elevation dimension, such that a smallest patch is positioned in a center of the aperture in the elevation dimension with patches of progressively increasing size extending on either side of that smallest patch to the elevation limits of the aperture on either side of that smallest patch. (i) configuring patches of a uniform size in the elevation dimension and different sizes in the azimuth dimension, such that a smallest patch is positioned in a center of the aperture in the azimuth dimension with patches of progressively increasing size extending on either side of that smallest patch to the azimuth limits of the aperture on either side of that smallest patch, or (ii) configuring patches of a uniform size in the azimuth dimension and different sizes in the elevation dimension, such that a smallest patch is positioned in a center of the aperture in the elevation dimension with patches of progressively increasing size extending on either side of that smallest patch to the elevation limits of the aperture on either side of that smallest patch.