公开(公告)号：US20230221422A1

公开(公告)日：2023-07-13

申请号：US18150534

申请日：2023-01-05

Applicant: STMICROELECTRONICS S.r.l.

Inventor： Francesca CARMINATI ,  Marco PASSONI ,  Beatrice ROSSI ,  Diego CARRERA ,  Pasqualina FRAGNETO

IPC: G01S7/526 ,  H04R29/00 ,  H04R3/04 ,  H04R17/10 ,  G01S15/06

CPC classification number: G01S7/526 ,  H04R29/001 ,  H04R3/04 ,  H04R17/10 ,  G01S15/06 ,  H04R2201/003

Abstract: A method of operating a PMUT electro-acoustical transducer, the method comprising: applying over an excitation interval to the transducer an excitation signal which is configured to emit corresponding ultrasound pulses towards a surrounding space, acquiring at a receiver reflected ultrasound pulses as reflected in said surrounding space, generating a reference echo signal, performing a cross-correlation of said acquired received ultrasound pulses with said reference echo signal, performing a measurement based on the cross-correlation results, in particular a measurement of the time of flight of the ultrasound pulses, wherein said reference echo is obtained by finding an oscillation frequency of the transmitter on the basis of a transmitter ringdown signal, finding an oscillation frequency of the receiver on the basis of a receiver ringdown signal, performing a frequency tuning respectively on the transmitter and the receiver on the basis of said respective oscillation frequencies, then sweeping an input frequency of the transmitter to find a frequency of the maximum displacement in the ringdown signal, performing a frequency tuning of the receiver at said frequency of the maximum displacement in the ringdown signal of the transmitter.