论文部分内容阅读
在锁相测距信道中,当接收信号低于某一电平后,测距漂移误差显著地增加。这种现象称为“测距漂移误差门限”效应;对应的电平,称为“测距漂移误差门限”电平。本文阐述了这种“门限”效应产生的物理过程及其数学表达式。讨论接收信号电平变化时,信道的寄生调制对测距漂移误差的影响。分析了信道中几个主要部件,如带通滤波器、中频放大器、限幅器、解调器等对测距漂移误差所起的作用。保持接收信道频率特性的对称和解调器的正交,采用小信号限幅,可以减小奇生调制,提高测距精度。
In the phase-locked ranging channel, the ranging drift error increases significantly when the received signal is below a certain level. This phenomenon is called the “ranging drift error threshold” effect; the corresponding level, called the “ranging drift error threshold” level. This article explains the physical processes and mathematical expressions that result from this “threshold” effect. Discuss the influence of the parasitic modulation of the channel on the error of ranging drift when the received signal level changes. The effects of several major components in the channel, such as band-pass filters, IF amplifiers, limiters and demodulators, are analyzed. Maintaining the symmetry of the frequency characteristics of the receive channel and the quadrature of the demodulator, small signal clipping is used to reduce the odd-handed modulation and improve the accuracy of ranging.