Manipulation of focal patterns in acoustic Soret type zone plate lens by using reference radius/phase effect.

•A free parameter (reference radius r0) allows obtaining a much finer focus.•When r0 is bigger than r1, an expansion of the focus along the longitudinal axis is achieved.•When r0 smaller than r1, a control of the Sidelobe Level can be achieve.•The prospect of these results are important in some medical applications.•Possibility to control a spatial frequency to obtain a finer focus.