无线调频发射器.doc

Tianjin University of Technology and Education 毕 业 设 计 专 业： 班级学号： 学生姓名： 指导教师： 二〇〇七 年 六 月  天津工程师范学院本科生毕业设计 无线调频发射器的设计 The Design of Wireless Frequency Modulation Transmitter 专业班级： 学生姓名： 指导教师： 系 别： 2007 年 6 月 摘 要 利用无线通信信道的远距离语音传输业务，是近年来发展很快的一门技术。由于语音业务对误码不敏感，可以采用调频方式发送信息。调频发射器可以使音频信息传送到附近的任意FM接收机。本设计中使用AT89S52控制调频发射的频率，选择了数码管显示发射的频率状态。选择了ROHM BH1415F集成电路产生调频调制发射信号的频率。芯片的主要特征:体积小，准确性高，而且容易产生发射频率。这个系统的各个部分可以进行深入的独立设计研究，现在把它们组合成一个典型的调频发射系统。 本设计使用模拟调频技术，在88MHz--98MHz的频段上，实现了线路输入语音信号的小功率远距离单工发送。系统发射功率大约20mW，发射距离大于20m，本系统可实现无明显失真的语音传输。 关键词：调频；语音传输；ROHM BH1415 ABSTRACT The remote audio service code through wireless communication channels is a fast developing technology in recent years. As the audio service code is not sensitive to the mistaken code, the frequency modulation can be used to send information.The FM Transmitter will allow almost any audio source to be transmitted to any nearby FM receiver. The AT89S52 to be used to control the transmission frequency. The LED was chosen, providing enough space for all output situations. The ROHM BH1415F integrated circuit was chosen to create the frequency modulated audio output signal. Chip features include: small size, accuracy, and easily programmed transmission frequency. These system components have been thoroughly researched separately and are now in the process of being integrated to produce a working prototype FM Transmitter. The simulating frequency modulation technique was adopted in the design .In the frequency interval of 88MHz---98 MHz, the audio signals can be sent out and received with the small power in a long distance .The emissive power of the system is about 20mW and the emissive distance is more than 20m.There is no obvious distortion in the audio transmission. Key Words：frequency modulation；audio transmission； ROHM BH1415F 目 录 1 引言 1 1.1 通信的发展 1 1.2 广播的发展现状 1 1.3 设计思路 2 2系统概述 3 2.1 系统功能要求 3 2.2系统组成 3 3 方案论证与比较 5 3.1 无线调频发射电路设计方案论证与选择 5 3.2 压控