A micromechanical ultrasonic distance sensor with >1 meter range

Ultrasonic distance sensors based on piezoceramic transducers have >;1m range and millimeter accuracy but require the use of bulky transducers. Existing micromachined sensors deliver inferior performance, with maximum range in the tens of centimeters. We present theory, design equations, and measured results for a micromechanical ultrasonic distance sensor which approaches the performance of piezoceramic-based solutions. The sensor has a maximum range >;1300mm and random errors (3σ) of <;1.7mm at 1.3m.