九、SAW卷积器和相关器 A.非线性工作三端和四端SAW卷积器(使起相关器作用)在扩展频谱通信和宽带雷达中已有广泛的用途,近来又扩展用于分组无线电通信系统。SAW功率在充分高的电平激励下,这些器件以非线性模式工作,对需要仔细研究的信号与接收机中的本地参考信号或编码作相关处理。信号本身包含有该编码的调制。和以上考虑的PTF相反,作大处理增益和/或保密通信的调制码可以是一个冗长的或快速变化的码。距离分辨率、数据率和处理增益都随 SAW convolvers and correlators A. Non-linear working The three-terminal and four-terminal SAW convolvers (which act as correlators) have found wide use in spread spectrum communications and wideband radars and have recently been extended for packet Radiocommunication system. SAW Power With a sufficiently high level of excitation, these devices operate in a non-linear mode, correlating the signals that need to be carefully studied with the local reference signals or codes in the receiver. The signal itself contains the coded modulation. In contrast to the PTF considered above, the modulation code that handles large gains and / or secure communications may be a lengthy or rapidly changing code. Distance resolution, data rate and processing gain are both