A MEMS Non-Planar Constant Beamwidth Ultrasonic Sensor Microarray
Matthew Meloche, Sazzadur Chowdhury · 2006
This paper develops the theory of a MEMS nonplanar intrinsically beamforming ultrasonic sensor microarray. The microarray exploits the geometrical properties of a doubly ruled surface to realize a constant beamwidth broadband directional sensitivity without microelectronic signal processing as required by conventional acoustic beamformers. The 1000 times 1000 mum2array consists of 25 (5 times 5) capacitive type ultrasonic sensors and can provide a constant beamwidth broadband beamforming in the 1.70-3.00 MHz frequency range. The tiered geometry has an out-of-plane angle of plusmn 10 degrees which translates into a 20 degree wide constant beamwidth broadband beam. The developed theory has been verified by extensive analytical and 3D FEA simulations using IntelliSuitetrade MEMS design tools. The device has excellent potential to be used in automotive collision avoidance applications