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Magnitude Locked Loop(unit3 passage C)A novel control loop which maintains the magnitude of a transferfunction constant is proposed. This loop is named as the magnitude locked loop (MLL). It is shown that it can perform most of the functions of the phase locked loop. Several configurations can be chosen for the transfer function. The best, selected for its minimization of error, is presented in this letter. C篇 锁幅环路 一个保持传递函数幅值不变的新奇控制环路被提出，这个环路就叫做锁幅环路，它可以执行锁相环路的绝大多数功能，而且有数个结构可以供传递函数选择，本文将会介绍最合适的，误差最小的一种结构。IntroductionThe MLL is a control loop that maintains the magnitude of a transfer function (TF) constant, irrespective of the input frequency. The basic configuration, consisting of a TF generator, rectifiers, and a comparator, generates a voltage which is a linear function of the input frequency. Because of the functional similarity of the MLL to the PLL, it is natural to compare the two. Unlike in the PLL, where the input frequency is compared with the frequency of the output of the VCO, in the MLL, the amplitude of the input signal is compared with that of the output of the TF generator. The role of the TF generator in the MLL is similar to that of the VOC in the PLL. It is important to note that to the MLL should necessarily be sinusoidal, unlike in the PLL. The major advantage of the MLL is the simplicity of its realization.介绍锁幅环路是一个不管输入频率为多少都保持传递函数常数不变的控制回路，其最基本的结构包括：传递函数发生器、整流器、和比较器。它会产生一个与输入频率呈线性关系的电压。将锁幅环路和锁相环路进行比较是很自然的由于它们两个功能上的相似性。但是不像在锁相环路中在电压控制振荡器下将电路的输入和输出频率作比较，在锁幅环路中，作比较的是输入信号和传函发生器输出信号的振幅。锁幅环路中传函发生器的角色和锁相环路中电压控制振荡器的角色类似。最重要的是要注意，不像锁相环路，锁幅环路得到的必然是正弦波。其主要的优点就是实现电路简单。 Circuit OperationFigure 3.7 shows the basic block diagram of the MLL. The amplitude of the sinusoids is extracted by rectification followed by low pass filtering. The average of a half rectification sinusoid=Vpeak/π. The average value of the input and that the TF generator outputs are compared. If negative feedback exists and the comparator gain is large enough, the two will be equal.电路工