Abstract
This article presents a fully integrated ultrasound system based on a single piezoelectric micromachined ultrasonic transducer (PMUT) monolithically fabricated with a 0.13~μ m complementary metal oxide semiconductor (CMOS) process analog front-end circuitry. The PMUT consists of an aluminum nitride, AlN, squared device with 80~μ m side that resonates at 2.4 MHz in liquid environment. The monolithic integration of the PMUT with the CMOS circuitry allows a reduction of the parasitic capacitance, a reduction of the electronic noise contribution and a clear improvement in the Signal-to Noise ratio (SNR 27 dB better) compared to a non-integrated equivalent system. A pulse-echo experiment with the single PMUT-on-CMOS for transmitting and sensing simultaneously is demonstrated, ensuring a 17.3 dB SNR, higher than the minimal necessary for accurate fingerprint images, paving the way towards a pixel sized imaging system with no need of multiple simultaneous PMUTs transmitters. Consuming only 0.3 mW and getting an input-referred noise of 3.26 mPa/√ Hz at 2.4 MHz, the proposed pulse-echo system achieves a competitive noise efficient factor in comparison with the state-of-the-art.
Original language | American English |
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Article number | 9154376 |
Pages (from-to) | 142785-142794 |
Number of pages | 10 |
Journal | IEEE Access |
Volume | 8 |
DOIs | |
Publication status | Published - 2020 |
Keywords
- AlN
- CMOS
- CMOS-MEMS
- piezoelectric on CMOS
- piezoelectrical resonator
- PMUT
- PMUT-on-CMOS
- ultrasound
- ultrasound transducers