缩写稿-数字频率合成器的设计.doc

毕业论文缩写稿 题目： 数字频率合成器的设计 学 生： 田 耀 青 学 号： 座机电话号码101 院 （系）： 职业教育师范学院 专 业： 电子信息工程 指导教师： 陈 晓 莉 2015 年 05月 30 日 数字频率合成器的设计 电子信息工程111班：田耀青 指导教师：陈晓莉 （陕西科技大学职业教育师范学院 陕西 西安 710021） 摘要：频率合成器是无线通信系统中一个很重要的模块，。它通过产生一系列与参考信号具有同样精度和稳定度的离散信号，为频率转换提供基准的本地振荡信号。频率合成器设计的优劣直接影响到无线通信收发机的性能、成本，故其实现方式一直给设计者提出挑战。 由频率合成技术获得的信号源具有高频率稳定度和准确度，并且能方便地改变频率，其中频率合成方法有直接式和间接式两种。锁相环频率合成器是目前应用较为广泛的一种频率合成技术。本文主要介绍74HC4046锁相环数字频率合成器的构成电路以及原理。74HC4046锁相环数字频率合成器主要由振荡源电路、固定分频器，1/Ｎ可预置分频器以及锁相环电路构成。其功能是将一给定频率的输入信号经频率合成后产生一系列的N 倍频率的输出信号。此频率合成器具有系统稳定、精确度高、较高的可选择性与实用性等特点。该方案简单易行且易于调试，具有较高的实用价值。 关键词：频率合成， 锁相环， 74HC4046， 分频器 Design of digital?frequency synthesizer Abstract：The frequency synthesizer is a very important module in the wireless communication system,It generates a series of discrete signals with the same accuracy and stability as the reference signal, and provides a reference for the frequency conversion local oscillating signal.?The pros and cons of the frequency synthesizer design has a direct influence on the wireless communication transceiver performance, cost, so the way to the designer challenge. The signal source synthesized by the frequency synthesizer has the high frequency stability and accuracy, and can change the frequency easily, and the synthetic method of frequency has two kinds of direct and indirect.The PLL frequency synthesizer is a widely used frequency synthesis technology at present..?This paper mainly introduces the circuit and principle of 74HC4046 PLL digital frequency synthesizer.?The 74HC4046 PLL digital frequency synthesizer is composed of the oscillating source, the fixed frequency divider, the 1/N of the preset frequency divider and the PLL circuit..?Its function is to generate a series of output signals of N times after frequency of the input signal of a given frequency. This frequency synthesizer has the characteristics of stability, accuracy, high selectivity and practicality. This scheme is simple and easy to debug, and has high practical value. Key wor