【摘要】 提出了一种利用空气中超声波非线性传播效应制作的、可产生高指向性可听声的新型声束扬声器。为提高其输出功率、缩短研发周期,以polyvinylidenefluoride(PVDF)膜作为换能器的发声部件,设计出了一种谐振频率可调的换能器。在此基础上,比较了换能器线性阵列与方形阵列的三维指向性问题,指出线性阵列无法像方形阵列一样产生预期的圆柱形声波传播空间分布,并由此指出声束扬声器的换能器阵列采用方形阵列设计较为合理。更多还原

【Abstract】 A novel audio beam loudspeaker which based on nonlinear propagation effects of ultrasonic in the air to generate audible sound with high directivity is presented. Polyvinylidene fluoride(PVDF) as acoustic generator, a transducer with tunable resonant frequency is designed to increase the output power and shorten the time of audio beam loudspeaker’s research and development. Furthermore, the three-dimensional directivity of linear transducer array and square transducer array is compared, and it is proved that square transducer array design is more reasonable for audio beam loudspeaker than linear transducer array design, for the reason of desired cylindrical sound wave space distribution can be generated, which can not be produced by linear transducer array.更多还原