【正文】 上情況和該生畢業(yè)設(shè)計(jì)過程中良好表現(xiàn)，成績(jī)?cè)u(píng)定為 95分，允許提交答辯。 評(píng)閱者 (簽字 )： 年 月 日 答辯委員會(huì)（小組）評(píng)語(yǔ)： 答辯委員會(huì)（小組）負(fù)責(zé)人 (簽字 )： 年 月 日 畢業(yè)設(shè)計(jì)說明書（論文）中文摘要 調(diào)頻發(fā)射機(jī)是一種常用的通信工具。調(diào)頻發(fā)射機(jī)的種類很多，模擬調(diào)頻發(fā)射機(jī)、半數(shù)字化調(diào)頻發(fā)射機(jī)，以及數(shù)字調(diào)頻發(fā)射機(jī)。數(shù)字調(diào)頻發(fā)射機(jī)運(yùn)用了 軟件無線電技術(shù)來實(shí)現(xiàn)音頻信號(hào)到射頻信號(hào)全數(shù)字化的調(diào)頻廣播發(fā)射機(jī)，調(diào)頻調(diào)制過程 DSP 控制 DDS（直接數(shù)字頻率合成器）來完成，實(shí)現(xiàn)了調(diào)制過程的數(shù)字化。 本次畢業(yè)設(shè)計(jì)主要是設(shè)計(jì)半數(shù)字調(diào)頻發(fā)射機(jī)。通過單片機(jī)預(yù)置數(shù)據(jù)存儲(chǔ)電臺(tái)，并控制 BH1415F，利用 BH1415F 內(nèi)部的數(shù)字鎖相環(huán)電路使頻率鎖定。 本畢業(yè)設(shè)計(jì)了可在 至 范圍內(nèi)任意設(shè)置發(fā)射頻率的數(shù)控調(diào)頻發(fā)射器，可預(yù)置 11個(gè)頻道，另外還具有立體聲 /立體聲控制功能。 關(guān)鍵字 單片機(jī) BH1415F 調(diào)頻發(fā)射機(jī) 頻率控制 畢業(yè)設(shè)計(jì)說明書（論文）外文摘要 Title The design and realization of FM transmitter Abstract The FM transmitter is a munication tool. The main function of the transmitter is to modulate the audio signal and the high frequency carrier for frequency modulation wave, amplify frequency modulation wave by power amplification and send the signal by antenna. There are three kinds of the FM transmitter. One kind is analog FM transmitter. The second is the semidigital FM transmitter. The third is digital FM transmitter. Digital FM transmitter is device that change digital audio signal into FM signal by using software. Analog FM transmitter takes analog technology. It has disadvantages of poor stability. Digital FM transmitter processes audio signal and code by technology of DSP(digital signal processor) and DDS (direct digital frequency synthesizer).So it plete to process the digital modulation. Semidigital FM transmitter takes digital control phase locked loop technology. I designed the Semidigital FM transmitter. A controller of the FM transmitter is STC89C51. The core FM ponent of the FM transmitter is digital PLL FM chip BH1415F produced by the ROHM pany. Through using BH1415F MCU preset data, the PLL will lock the transmitter frequency. So the frequency of the FM transmitter is very stable. The FM transmitter has five digital tubes to display, and has keyboard to input the required frequency. The operation of the FM transmitter is very convenient. Transmitting frequency of most of the college campus FM radio transmitter is fixed. Stability of single is poor. In the design, the frequency of FM transmitter is from 80 MHZ to . The FM radio transmitter can be preset 11 channels. By paring with traditional FM, the FM transmitter is more flexible and reliable. The FM transmitter can be widely applied to the school radio broadcast, television director at the scene, car radio, wireless speech etc. Keywords： MCU BH1415F FM transmitter Channel control 本科畢業(yè)設(shè)計(jì)說明書（論文） 第 1 頁(yè) 共 2 頁(yè) 目 次 1 緒論 ............................................................ 1 2 調(diào)頻發(fā)射機(jī)的技術(shù)原理及要求 ...................................... 2 調(diào)頻發(fā)射機(jī)的工作原理和技術(shù)特點(diǎn) ................................ 2 調(diào)頻發(fā)射機(jī)的分類 ............................................... 2 半數(shù)字調(diào)頻發(fā)射機(jī)的技術(shù)優(yōu)勢(shì) ...................................... 3 設(shè)計(jì)方案 ...................................................... 3 調(diào)頻發(fā)射模塊設(shè)計(jì)方案的選擇 .................................. 3 MCU 控制電路設(shè)計(jì)方案的選擇 ................................... 6 技術(shù)功能實(shí)現(xiàn)要求 .............................................. 7 調(diào)頻發(fā)射機(jī)的主要技術(shù)參數(shù)指標(biāo) .................................. 7 3 調(diào)頻發(fā)射機(jī)的硬件實(shí)現(xiàn) ............................................ 8 調(diào)頻發(fā)射機(jī)的硬件系統(tǒng)總體框圖 .................................. 8 STC89C51RC 的技術(shù)特點(diǎn)與功能 .................................... 8 STC89C51 的主要技術(shù)特點(diǎn) ...................................... 9 STC89C51 引腳說明 ............................................ 9 STC89C51 單片機(jī)主要功能 ..................................... 10 調(diào)頻發(fā)射機(jī)單片機(jī)控制電路 ..................................... 11 BH1415F 的功能與技術(shù)特點(diǎn) ...................................... 12 BH1415F 的主要優(yōu)點(diǎn) .......................................... 12 BH1415F 引腳功能說明 ........................................ 12 BH1415F 主要功能電路 .......................................... 13 限幅電路 ................................................... 14 預(yù)加重電路 ................................................. 14 立體聲調(diào)頻電路 ............................................. 15 低通濾波電路 ............................................... 16 BH1415 鎖相環(huán)電路 ........................................... 16 本科畢業(yè)設(shè)計(jì)說明書（論文） 第 2 頁(yè) 共 2 頁(yè) BH1415F 的調(diào)頻發(fā)射電路 ........................................ 17 4 其他硬件單元設(shè)計(jì) ............................................... 19 電源電路單元 ................................................. 19 功率放大發(fā)射 電路單元 ......................................... 20 無線傳播半徑參照表 ........................................... 21 天線阻抗匹配 ............................................... 21 信號(hào)輸入電路單元 ............................................. 22 音頻信號(hào)輸入電路 ........................................... 22 麥克風(fēng)信號(hào)輸入電路 ......................................... 22 數(shù)碼管的顯示電路單元 ......................................... 23 5 技術(shù)軟件實(shí)現(xiàn) ................................................... 25 BH1415F 頻率控制方法 .......................................... 25 主程序流程圖 ................................................. 26 動(dòng)態(tài)掃描顯示子程序 ........................................... 27 BH1415 寫頻率數(shù)據(jù)子程序 ....................................... 28 頻率數(shù)據(jù)存儲(chǔ)子程序 ........................................... 30 6 調(diào)頻發(fā)射機(jī)調(diào)試 ................................................. 31 本課題設(shè)計(jì)的調(diào)頻發(fā)射機(jī) ........................................ 31 發(fā)射機(jī)硬件調(diào)試 ................................................ 31 發(fā)射機(jī)軟件程序調(diào)試 ............................................. 32 結(jié) 論 ............................................................ 34 致 謝 ............................................................ 35 參考文獻(xiàn) .......................................................... 36 附錄一 BH1415F 技術(shù)指標(biāo) ........................................