一种数字式声频定向扬声器调制方法  

Digital Modulation Method of Directional Loudspeaker

作　　者：蒲刚[1] 姜丽峰[1] 

机构地区：[1]电子科技大学空天科学技术研究院,四川成都611731

出　　处：《电声技术》2013年第3期13-17,共5页Audio Engineering

摘　　要：提出一种数字式声频定向扬声器调制方法,采用频率为超声波换能器谐振频率的方波信号来控制桥式功率输出开关,同时将原音频信号加上一定的直流偏置并经D类功率放大器放大后作为桥式功率输出开关的电源,之后将桥式功率输出开关的输出经匹配和滤波后送至超声换能器。理论分析和实验结果表明:提出的数字式声频定向扬声器调制方法在保证输出信号质量的同时能够降低58%～67%的功耗,很好地解决了声频定向扬声器的功率放大问题。An digital modulation method of directional loudspeaker is proposed. A square wave whose frequency is the same with the resonant frequency of ultrasonic transducer is used to control the bridge power switch, while the original audio signal with a DC bias is amplified by the Class D amplifier and power to the bridge power switch. The output of the bridge power switch drives ultrasonic transducer after matching and filtering. Theoretical analysis and experimental results show that： the proposed digital modulation method of directional loudspeaker can reduce the power consumption of 58% -67% while ensuring the quality of output signal. It＇ s a good solution to the directional loudspeaker power amplifier problem.

关 键 词：声频定向扬声器 方波 D类功率放大器 功耗 

分 类 号：TN643[电子电信—电路与系统]