Ultrasonic transducer

An ultrasonic transducer, comprising:

• a piezoelectric element with an upper surface and a lower surface opposite to each other through said piezoelectric element and a lateral surface connecting said upper surface and said lower surface;
• a carrier with an inner surface and an outer surface opposite to each other through said carrier, wherein said upper surface of said piezoelectric element is connected with said inner surface of said carrier and has bending resonant frequencies and thickness resonant frequencies;
• and
• an acoustic matching layer connected with said outer surface of said carrier and having a first resonant matching part and a second resonant matching part, wherein said second resonant matching part is at a center of said upper surface of said piezoelectric element and said first resonant matching part surrounds said second resonant matching part on said upper surface of said piezoelectric element, and a thickness of said first resonant matching part in a direction perpendicular to said outer surface is greater than a thickness of said second resonant matching part in said direction, and said thickness of said first resonant matching part matches one of said bending resonant frequency formed by said piezoelectric element and carrier, and said thickness of said second resonant matching part matches another said bending resonant frequency or one of said thickness resonant frequency formed by said piezoelectric element and said carrier.