【摘要】 为了解决大阵列相控的功率、效率及散热问题,促进相控声场的非接触物体操控及其在医学超声中的实际应用,设计了一种PWM型D类超声宽带功率放大器.对阻性和抗性负载的输出波形开展谐波失真、负载电压和输出功率的测量结果表明:该电路可对20～400 kHz的中低频超声输入信号进行功率放大,其最大输出功率可达46 W,效率超过78%.该电路具有输出内阻小、阻抗匹配简单、相位保持度高、功率损耗低和发热小的优点,可为超声技术在生物医学中的应用提供电路基础,实现大规模相控阵列的精确驱动,具有良好的推广价值.更多还原

【Abstract】 In order to solve the problems of power,efficiency and heat dissipation for the phased transducer array in non-contact object manipulation and its practical applications in medical ultrasound,a PWM style class-D ultrasonic broadband power amplifier is designed and implemented. The waveforms of the resistive and resistant loads are collected to analyze the characteristics of the harmonic distortion,the load voltage and the output power. The measured results show that the class-D ultrasonic power amplifier can work in the medium and low frequency with the range from 20 kHz to 400 kHz. The maximum output power is up to 46 W with the efficiency higher than 78%. The class-D ultrasonic power amplifier has the advantages of low output resistance,easy resistance matching,high phase retention,low power loss and temperature rising. This design provides a basic circuit for the accurate driving of large-scale phased arrays,exhibiting prosperous applications in biomedical engineering.更多还原