EP 0973149 A2 20000119 - Ultrasonic transducers
Title (en)
Ultrasonic transducers
Title (de)
Ultraschallwandlern
Title (fr)
Transducteurs ultrasonores
Publication
Application
Priority
- US 11627198 A 19980716
- US 30020099 A 19990427
Abstract (en)
Sonic transducers utilize resonant cavities of varying depths to achieve wide operational bandwidth. The transducers (29) may include a conductive membrane (38) spaced apart from one or more backplate electrodes (32a,32b). In one approach, spacing is achieved using a dielectric spacer (34) having a series of depressions (36) arranged in a pattern, the depressions forming cavities each resonant at a predetermined frequency. In another approach, the conductive membrane (62) is piezoelectrically active, and the transducer is simultaneously driven in both piezoelectric and electrostatic modes. <IMAGE>
IPC 1-7
IPC 8 full level
B06B 1/02 (2006.01); B06B 1/06 (2006.01); H04R 17/00 (2006.01); H04R 17/10 (2006.01)
CPC (source: EP)
B06B 1/0292 (2013.01); B06B 1/0614 (2013.01); B06B 1/0688 (2013.01)
Designated contracting state (EPC)
BE DE FR GB NL
DOCDB simple family (publication)
EP 0973149 A2 20000119; EP 0973149 A3 20001227; JP 2000050392 A 20000218; JP 4294798 B2 20090715
DOCDB simple family (application)
EP 99305633 A 19990715; JP 19638299 A 19990709