ARRAYS FOR AIRBORNE 100 KHZ ULTRASOUND

An investigation into methods of producing ultrasonic phased arrays resonating at 100 kHz using capacitive transducers is described here. The backplate texture is one of the most critical parameters determining the performance of these transducers, and transducer arrays were produced using a variety of methods to generate an appropriate backplate texture, including etching, chemical machining, silk-screening, shot-peening and machining. The most successful method involved the use of a proprietary conductive plant, and several arrays with both lambda and lambda/2 element spacings were produced and tested. The transducers can detect targets at distances of up to 1.8 m and two-dimensional range maps were constructed from the received signals using digital beam-forming.