Sound Retrieval Using 24 GHz FMCW Radar

This paper investigates the use of radar techniques for recovering low frequency audio signals by measuring the vibration induced in objects exposed to sound pressure waves. A sound wave emitted by a speaker is recovered by measuring the small-scale displacement vibrations transmitted into a reflective surface that is being analyzed by a commercial FMCW radar at 24 GHz, bandwidth of 300 MHz and sweep time of 300 µs. Experimental validations are provided to show the effectiveness of the proposed method.