ULTRASONIC MEMS TRANSMITTER AND RECEIVER WITH A POLYMER MEMBRANE

摘要

An ultrasonic transmitter and receiver includes a MEMS composite transducer (100). The MEMS composite transducer includes a substrate (110). Portions of the substrate define an outer boundary (114) of a cavity (115). A first MEMS transducing member (120) includes a first size. A first portion (121) of the first MEMS transducing member is anchored to the substrate. A second portion (122) of the first MEMS transducing member extends over at least a portion of the cavity and is free to move relative to the cavity. A second MEMS transducing member includes a second size that is smaller than the first size of the first MEMS transducing member. A first portion of the second MEMS transducing member is anchored to the substrate. A second portion of the second MEMS transducing member extends over at least a portion of the cavity and is free to move relative to the cavity. A compliant membrane (130) is positioned in contact with the first and second MEMS transducing members. A first portion (131) of the compliant membrane covers the first and second MEMS transducing members. A second portion (132) of the compliant membrane is anchored to the substrate. The ultrasonic transmitter and receiver comprises as well separate circuitry (40-45) for transmitting and receiving the ultrasonic signals.