Patent ID: 8667846

Claim:
A method of operating an ultrasonic transmitter and receiver, the method comprising: providing a MEMS composite transducer comprising a substrate, portions of the substrate defining an outer boundary of a cavity; a first MEMS transducing member including a first size, a first portion of the first MEMS transducing member being anchored to the substrate, a second portion of the first MEMS transducing member extending over at least a portion of the cavity, the second portion of the first MEMS transducing member being free to move relative to the cavity; a second MEMS transducing member including a second size smaller than the first size, a first portion of the second MEMS transducing member being anchored to the substrate, a second portion of the second MEMS transducing member extending over at least a portion of the cavity, the second portion of the second MEMS transducing member being free to move relative to the cavity; and a compliant membrane positioned in contact with the first and second MEMS transducing members, a first portion of the compliant membrane covering the first and second MEMS transducing members, and a second portion of the compliant membrane being anchored to the substrate; sending electrical pulses to the first MEMS transducing member, thereby causing the first MEMS transducing member and the compliant membrane to vibrate; transmitting the vibrations of the first MEMS transducing member and the compliant membrane to an object; receiving echo signals from the object; and converting the received echo signals into electrical signals by the second MEMS transducing member.