基于模拟乘法器的超声调幅器实现

Implementation of ultrasonic amplitude modulator based on analog multiplier

将声音信号调制到超声载波信号上,然后通过超声换能器发射到空气中,由于超声波在空气中具有自解调效应,可产生具有方向性的可听声波,在正对发生器的方向能够听到正常的音频信号,而在其他方向听不到声音信号。作为声波定向传输系统的关键组成部分,文章的主要目的是设计抑制载波的振幅调制器,得到合适的超声已调信号。

The sound signal is modulated onto an ultrasonic carrier signal and then transmitted through the ultrasonic transducer into the air. Since the ultrasonic wave has a self-demodulation effect in the air, a directional sound wave can be generated. A normal audio signal can be heard in the direction of the generator, and no audio signal can be heard in the other direction. As a key component of the acoustic directional transmission system, the main purpose of this paper is to design an amplitude modulator that suppresses the carrier and obtain a suitable ultrasonic modulated signal.