Low-loss ultrasound transmission through glass assisted by resonance

•An arrangement for ultrasound transmission through glass is demonstrated.•Low-loss achieved at resonances in the glass plate and a closed cavity.•Transmission frequency is tuneable by geometrical parameter variations. We have investigated transmission of ultrasound signals from a speaker in air through a 400 µm thick borosilicate glass plate, similar to those found in consumer electronics products such as mobile phones and tablets. In order to enhance transmission, we took advantage of resonances in the glass plate and a cavity, which is placed between the glass and the microphone. The results show that it is possible to achieve transmission of a signal with bandwidth of approximately 5 kHz with less than −10 dB attenuation, and only −2 dB attenuation at the resonance peak frequency. With more optimized assembly the attenuation can be further reduced. Finite element simulations and analytical considerations show that there are two main resonance peaks, attributed to the glass resonance and cavity resonance, respectively. The geometry can be tuned to exploit the synergy of these two resonances in order to tailor the peak frequency, the bandwidth and to optimize transmission.