Broadband piezoelectric ultrasonic transducer for radiating in air

US4677337A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Peter Kleinschmidt · Munich, DE
• Valentin Magori · Gernsheim, DE

Key dates

• Filing date: Oct 29, 1986
• Grant date: Jun 30, 1987
• Expiry date: Oct 29, 2006

Classification

• Technology area (CPC G): Physics
• CPC primary: G10K9/122
• WIPO field: Other consumer goods
• WIPO sector: Other fields

Abstract

A piezoelectric ultrasonic transducer for radiating ultrasonic energy in the medium of air has a number of piezoceramic ultrasonic radiators disposed in registry within a dimensionally stable carrier block which has an intrinsic acoustic impedance which is lower by a factor of at least eight than that of the piezoceramic material and which has a high mechanical attenuation 1/Q.sub.m greater than approximately 0.05. The carrier block is yieldable at at least one closed face thereof for emission and/or reception of ultrasonic energy. The piezoelectric transducer elements may be divided into a number of side-by-side elements which may be individually energized, or may have electrodes connected in series for energizing the individual transducer elements in common. The combined operation of the ultrasonic transducer elements within the carrier block results in an ultrasonic transducer having broadband characteristics matched for ultrasonic transmission in the medium of air of short ultrasonic waveforms and for receiving ultrasonic energy for near-distance detection.