Low Cost, Wideband Ultrasonic Transmitter and Receiver for Array Signal Processing Applications

This paper presents a low-cost, wideband ultrasonic transmitter for in-air ultrasonic applications based on a conventional narrowband piezoceramic transducer with a LR circuit modification. An analytic method for calculation of the optimum circuit parameters for bandwidth expansion of the ceramic ultrasonic transmitter is described, together with experimental data proving the viability of the method. A low cost wideband ultrasonic receiver array is also presented. The results of the first characterization of MEMs microphones in the ultrasonic band and their use in a sensor array for ultrasonic Array Signal Processing applications is presented. The study presents examples of prototype performance in ultrasonic indoor applications.