一种小型高效水声发射机的设计与实现

Design and Implementation of A Small and High Efficient Underwater Acoustic Transmitter

针对便携式水声通信设备小体积和高效率的要求,设计并实现了一种水声信号发射机;分析了系统发射功率要求,采用AD公司新款采用PDM调制的D类音频功放SSM2305,能够实现可调的输出功率;根据换能器和音频功放的阻抗特性,对调谐匹配及脉冲变压器的选型进行了分析,采用串联调谐和脉冲变压器进行匹配滤波;该水声发射机的发射信号采用2FSK调制并进行了水池实验,测得SSM2305最高工作频率可达30kHz,发射机系统电声转换效率为27%,表明该发射机可以应用于便携式水声通信设备。

To satisfy the demand of portable underwater acoustic communication equipment for small size and high efficiency, an underwater acoustic transmitter is designed and implemented. The transmission power requirement is analyzed, and a new Class D audio amplifier SSM2305 with PDM modulation is adopted, thus adjustable output power can be achieved. According to the impedance of the transducer and SSM2305, the tuning matching and the pulse transformer are analyzed, and then matched filtering circuit is designed. The transmit signal is modulation by 2FSK, and the transmitter is verified in the tank experiment which shows that, the SSM2305 can operate at the frequency of 30kHz, and the systemic electro--acoustic conversion efficiency is 27%, so the transmitter can be used in portable underwater acoustic communication equipment.