【正文】 畢業(yè)論文 Tianjin University of Technology and Education 天津工程師范學(xué)院本科生畢業(yè)設(shè)計 無線調(diào)頻發(fā)射器的設(shè)計 The Design of Wireless Frequency Modulation Transmitter 畢業(yè)論文 摘 要 利用無線通信信道的遠距離語音傳輸業(yè)務(wù)，是近年來發(fā)展很快的一門技術(shù)。由于語音業(yè)務(wù)對誤碼不敏感，可以采用調(diào)頻方式發(fā)送信息。調(diào)頻發(fā)射器可以使音頻信息傳送到附近的任意 FM接收機。本設(shè) 計中使用 AT89S52控制調(diào)頻發(fā)射的頻率，選擇了數(shù)碼管顯示發(fā)射的頻率狀態(tài)。 選擇了 ROHM BH1415F 集成電路產(chǎn)生 調(diào)頻調(diào)制發(fā)射信號的頻率。 芯片的主要特征 :體積小 ， 準確性高 ， 而且容易產(chǎn)生發(fā)射頻率。這個系統(tǒng)的各個部分可以進行深入的獨立設(shè)計研究，現(xiàn)在把它們組合成一個典型的調(diào)頻發(fā)射系統(tǒng)。 本設(shè)計使用模擬調(diào)頻技術(shù)，在 88MHz98MHz 的頻段上，實現(xiàn)了線路輸入語音信號的小功率遠距離單工發(fā)送。系統(tǒng)發(fā)射功率大約 20mW，發(fā)射距離大于 20m，本系統(tǒng)可實現(xiàn)無明顯失真的語音傳輸。 關(guān)鍵詞 ： 調(diào)頻；語音傳輸； ROHM BH1415 畢業(yè)論文 ABSTRACT The remote audio service code through wireless munication 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 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 ponents have been thoroughly researched separate ly 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 88MHz98 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 is no obvious distortion in the audio transmission. Key Words： frequency modulation； audio transmission； ROHM BH1415F 畢業(yè)論文 目 錄 1 引言 ............................................................................................................................... 1 通信的發(fā)展 ........................................................................................................ 1 廣播的發(fā)展現(xiàn)狀 ................................................................................................ 1 設(shè)計思路 ............................................................................................................ 2 2 系統(tǒng)概述 ........................................................................................................................ 3 系統(tǒng)功能要求 .................................................................................................... 3 系統(tǒng)組成 ............................................................................................................. 3 3 方案論證與比較 ........................................................................................................... 5 無線調(diào)頻發(fā)射電路設(shè)計方案論證與選擇 ........................................................ 5 壓控振蕩器方案論證與選擇 ............................................................................ 6 4 系統(tǒng)硬件電路的設(shè)計 ................................................................................................... 7 單片機控制電路 ................................................................................................ 7 內(nèi)部結(jié)構(gòu) ................................................................................................. 7 引腳功能 ................................................................................................. 9 調(diào)頻調(diào)制發(fā)射電路 .......................................................................................... 11 調(diào)頻調(diào)制電路的特點 ........................................................................... 11 結(jié)構(gòu)圖 ................................................................................................... 11 允許的最大值 ....................................................................................... 12 工作范圍 ............................................................................................... 12 調(diào)頻調(diào)制發(fā)射電路 的組成 ................................................................... 12 鍵盤部分 .......................................................................................................... 14 單片機鍵盤和鍵盤接口概述 ............................................................... 14 單片機鍵 盤接口和鍵功能的實現(xiàn) ....................................................... 15 LC 振蕩電路 ................................................................................................... 16 調(diào)頻放大電路 .................................................................................................. 17 電源模塊設(shè)計 .................................................................................................. 17 單元電源電路設(shè)計 ............................................................................... 17 直流穩(wěn)壓電源的檢測 ........................................................................... 17 5 系統(tǒng)程序的設(shè)計 ......................................................................................................... 18 畢業(yè)論文 主程序 .............................................................................................................. 18 延時子程序 ...................................................................................................... 19 LED 動態(tài)掃描子程序 ....................................................................................... 19 頻率數(shù)據(jù)轉(zhuǎn)換子程序 ...................................................................................... 19 控制命令合成子程序 ...................................................................................... 19 BH1415F 字節(jié)寫入子程序 ............................................................................... 20 查鍵子程序 ...................................................................................................... 21 6 系統(tǒng)調(diào)試及性能分析 ................................................................................................. 23 硬件調(diào)試 .........................