摘要：本课题主要是通过QN8027芯片设计的电路为低功率调频发射机QN8027作为可编程调频发射机模块。任何FM接收装置都可以接收作为测试用无线电的信道。发射模块可通过I2C接口建立发射通道,可作为FM发射机或QN8027芯片测试台使用。本课题主要是采用智能的调频发射机的高度集成的智能可编程模块为其提供外稳定可靠简单耐用的围电路,实现小功率FM环绕立体声信号混编调和抗干扰高效率传输的目的。

This topic is mainly through the QN8027 chip design circuit for low power FM transmitter QN8027 as programmable frequency modulation transmitter module. Any FM receiving device can receive channel, which is used as a radio for testing. The transmitting module can set up the transmitting channel through the I2C interface, which can be used as the FM transmitter or the QN8027 chip test stand. This topic mainly uses the intelligent FM transmitter module to provide the peripheral circuit to achieve the purpose of FM transmission. All over the world, frequency resources are relatively limited, so each country must strictly limit the use of frequency, leading to the use of traditional high-power FM broadcasting frequency resource constraints changing, making FM broadcasting technology to more dense cloth, low work rate, the same frequency, synchronization, the same characteristics of the small characteristics of the small Power FM FM Synchronous Broadcasting, so the transmission power can also be reduced to several Watt. The power of the small power FM FM Synchronous Broadcasting is relatively small, and the reflected wave field intensity can also reduce to the average level of the interference, effectively eliminate the multipath interference and eliminate a lot of shadow areas, and the small power radiation is relatively easy to plan, which can effectively improve the effective utilization of the spectrum and make the group effective. The condition of single frequency network is reduced, which provides effective conditions for multiple short distance broadcasting.

目  录

1.概述 1

1.1调频通信现状 1

1.2课题研究目的及意义 1

1.3课题主要研究内容 1

2.FM调频发射电路整体设计 2

2.1整体电路系统框图 2

2.2设计要求 3

3.硬件电路设计 3

3.1.单片机控制电路设计 3

3.1.1. 稳压器机介绍 3

3.1.2.应用电路设计 5

3.2.调频发射电路设计 6

3.2.1. QN8027调频发射芯片介 6

3.2.2.调频发射模块应用设计 6

3.3.人机交互电路设计 7

3.3.1. 差分放大电路设计 7

3.3.2. 应用电路设计 9

3.4. 24C02存储电路设计 9

3.5.语音放大滤波电路设计 10

3.6.电源及负压发生电路设计 12

3.6.1. 电源电路设计 12

3.6.2. 负压发生电路设计 12

4.控制软件设计 13

5.电路测试与分析论证 14

6.全文总结 15

致  谢 16

参考文献 17

附录 硬件原理图 18

1. 概述

QN8027 作为可编程调频发射模块。 任何FM接收装置都可以进行频道接收，就是作为收音机用于测试。发射模块可以通过I2C接口设置发射频道，可以作为调频发射台用，也可以作为QN8027芯片实验台使用。本次课题主要用到智能调频发射模块通过提供外围电路来达到调频发射的应用目的。

1.1调频通信现状

现代社会早已进入到信息时代，人们的通讯方式也渐渐被不断更新的技术所优化，社会高速发展越来越倾向于依赖高度灵敏的通讯速度，信息传播能力已经成为人们生活中重要的生产力之一。1930s，调制解调方式开始应用到无线广播通信中，当时是将信号调幅技术【幅度调制技术】进行优化后，更新为80年代左右的信号调频技术【频率调制技术】，非常有效的降低了中波广播信噪比非常有效的降低了非常串台非常有效的降低了频带分配过少等各种问题，调频FM广播具有非常宽的动态范围调频FM广播具有保真度高调频FM广播具有精准串台调频FM广播具有低信噪比功能，而且抗干扰能力很强，这些优点正是城市FM广播能力越来越强的原因，这类大功率跳频模式，其发射功率直线提升到2KW、4KW，与以前相比实现了超高覆盖率和非常清晰的有效接收效果。