Patent ID: 7477572

Claim:
An electro-acoustic transducer comprising a plurality of electrostatic micro-cells, characterised in that said micro-cells are arranged in homogeneous groups (A, B, C) of micro-cells having the same geometrical characteristics, each group comprising micro-cells having geometries different from the geometry of the micro-cells of the other group or groups such that the micro-cells of one group (A) have a resonance frequency different from the resonance frequency of the micro-cells of the other group or groups (B, C), the micro-cells of the groups (A, B, C) are constructed and arranged with shapes and dimensions so as to resonate and constructively interfere at frequencies above 15 MHz, wherein the electro-acoustic transducer is constructed and arranged to be acoustically coupled with a liquid and the layout of the micro-cells of each group (A) with respect to the micro-cells of the other group or groups (B, C) is such that, when the micro-cells are excited, the average pressure transmitted by the transducer has a bandwidth larger than 80%.