基于模拟乘法器和同步检波电路的研究

Based on the Research of Analog Multiplier and Synchronous Detection Circuit

模拟乘法器有两个输入端和一个输出端,且输出电压与这两个输入端的电压的乘积成正比,公式表示如下:u0=kui1ui2式中k为比列系数,可以取正值也可以取负值。当k取正值时,为同相乘法器;当k取负值时,为反相乘法器。能实现乘法器的方法很多,文章主要介绍变跨导式模拟乘法器,这是由于该乘法器电路结构简单、容易制成集成电路以及工作频率比较高,已被广泛使用。同步检波器是一种小信号线性检波器,其核心组成结构是由一个双差分放大电路构成的模拟乘法器,它还包括副载波恢复电路和低通滤波器(LPF)等构成。同步检波器可以对一般调幅波进行解调,也可以对平衡调幅波进行解调[1]。

Analog multiplier has two input and an output terminal, and the output voltage and the product of the two at the inputvoltage is proportional to the, shown by the following formula：u0 =kui1ui2.Type of ratio coefficient of the column, can positively canalso be negative. When positively, with multiplication multiplier; When negative, for the multiplication. A lot of methods can realizemultiplier, this paper mainly introduces the variable transconductance type analog multiplier, this is due to the multiplier circuitstructure is simple, easy to make integrated circuits and the working frequency is higher, has been widely used. Synchronous detectoris a kind of small signal linear detector, its core structure is composed of a double differential amplifier circuit, analog multiplier, italso includes subcarrier recovery circuit and low pass filter （LPF）, etc. Synchronous detector can undertake demodulation of generalamplitude modulation wave, also can undertake demodulation of balance amplitude modulation wave.