A data transmission device includes a coder configured to code the data into a multifrequency signal. A first array of ultrasonic transducers with a vibrating membrane is disposed on a first surface of a wafer. The first array configured to convert the signal into a multifrequency acoustic signal propagating in the wafer. A second array of ultrasonic transducers is disposed on a second surface of the wafer. The second array includes at least two assemblies of vibrating membrane ultrasonic transducers having resonance frequencies equal to two different frequencies of the multifrequency signal.