加州穆尔森林:谁能帮着翻译下面这篇文章?
本文介绍了基于PLL的扫频仪的设计方法。设计中,扫频信号源采用集成所相环频率合成器MC145151芯片,次选分离环路滤波器LPF和压控振荡器VCO来实现。另外本扫频仪以单片机89C51为控制核心,实现了扫频频率的步进调整;键盘使用行列扫描非编码方式键盘,通过扩展单片机的IO口来实现;采用液晶显示电路来实现频率数显、被测网络幅频特性与相频特性的数显。设计基本达到了数字化,成本也不高,如有需要的话还可以设置打印接口电路,将特性曲线打印出来,较传统的模拟扫频仪方便了许多。
Sweep appearance call frequency characteristic tester too frequently , use measurement for a the characteristic and characteristic frequently of phase frequently to examine the network, it is the commonly used electron that measures the apparatus . A traditional one sweep the appearance costs an arm and a leg frequently , can't receive the characteristic frequently of the looks directly while being analog, let alone the frequency of printing network responds the curve, give and use bringing a great deal of inconvenience. For this reason , have designed and swept the appearance frequently digitally.
This text has recommended being based on PLL to sweep the design method of the appearance frequently. In the design, sweep the signal source adopts and integrates and surrounds the frequency synthesizer MC145151 chip frequently, time select , separate cycle wave filter LPF and voltage-controlled oscillator VCO come on , realize. Sweep appearance regard one-chip computer 89C51 as core of controlling frequently , realize , sweep frequency walk into , change frequently originally in addition; The keyboard uses the ranks to scan and does not encode the way keyboard , realize through IO mouth expanding the one-chip computer; Adopt liquid crystal reveal circuit come , realize frequency count apparent , examine into network pieces of characteristic frequently and looks the number of the characteristic is apparent frequently. Having designed and basically reached digitization, the cost is not high, if need can also set up and print the circuit of interface , print the curve of characteristic out, more traditional simulation is swept frequently the appearance has facilitated much more.