雙音多頻調頻發射機

電子機電論文編號:JD991   論文字數:18777,頁數:37

目錄
目錄 1
引言 1
1  方案選擇與論證 3
1.1 調頻發射電路的選擇 3
1.2 調頻發射電路芯片的選擇 3
2 FM通信理論 5
2.1 調頻廣播的歷史 6
2.2調頻廣播的特點 7
2.3調頻廣播的標準 8
2.4調頻系統的一般方框圖 9
2.5調頻發射機原理 9
3 系統硬件組成 10
3.1 系統的基本原理 10
3.2 控制電路 12
3.4 鎖相環頻率合成電路BU2618FV 18
3.5 調頻立體聲的調制原理 21
4 設計和調試應注意的問題 26
4.1 BA1404設計時應注意以下幾點: 26
4.2 PCB及電路抗干擾措施  27
4.3 調試過程 27
5  結論 29
謝 辭 31
參考文獻 32
附錄 33

摘  要
 
 本文設計的是雙音多頻調頻發射機，總的組成是：由單片機控制電路，雙音多頻信號編碼電路，瑣相環頻率合成器組成的電路調頻立體聲芯片組成的調頻電路和音頻提取電路。雙音多頻電路產生的信號和音頻提取電路提取的音頻信號，分別進入調頻立體聲芯片的左右聲道進行調頻。調頻電路的壓控振蕩電路與瑣相環頻率合成器組成的電路構成閉合瑣相環，它的作用提供頻率穩定的調頻信號。 這種雙音頻通信具有控制簡單，實施方便，傳輸可靠，而且造價低廉的特點。文章首先介紹了FM的通信理論，再介紹雙音多頻接收發送器MT8888C 的基本工作原理和常用的工作模式, 然后以實現收發DTM F 信號為例給出了MT8888C 與89C51 的典型接口電路和控制軟件。其之，介紹一種采用鎖相環（PLL）頻率合成器(BU2618FV)和89C51單片機控制的調頻發射機，并介紹介紹了鎖相環集成電路（BU2618FV）的性能和典型應用。最后介紹了BA1404，BA1404 是日本ROHM 公司生產的為數不多的調頻發射集成電路之一。它是將立體聲調制、FM 調制和RF 放大功能集成在一個芯片上制成的。本文詳細論述了具有廣泛應用的立體聲調頻發射集成電路BA1404 的結構組成和工作原理,并給出了典型的應用電路。

關鍵詞：雙音多頻；MT8888；89C51；瑣相環頻率合成器BU2618FV；
      調頻立體聲

 Abstract

 What this text designed is much frequency modulation transmitters frequently of a pair of sound , total composition is: By the control circuit of one-chip computer, pairs of sound many signal encode circuit is trivial to surround frequency circuit frequency modulation stereo frequency modulation circuit and audio frequency that chip makes up that synthesizer make up draw the circuit frequently. Pairs of sound many signal and audio frequency that the circuit produce drew the audio frequency signal that the circuit is drawn frequently, enter frequency modulation stereo chip the sound channel goes on frequency modulation from side to side separately. Frequency modulation circuit voltage-controlled to shake circuit with trivial to surround frequency circuit that synthesizer make up is it close trivial looks ring to form, its function offers the steady frequency modulation signal of frequency. These kind of audio frequency communication is it control simple to have, it is convenient to implement, it is reliable to transmit, and the characteristic with cheap fabrication cost. The article introduces communication theory of FM at first, recommend one more pair of sound receive the basic operation principle of telephone transmitter MT8888C and commonly used work pattern frequently more, then regard realizing receiving and dispatching DTM F signal as the typical interface circuit that the example provides MT8888C and 89C51 and control the software. Its, introduce one kind phase locking of adopting ring frequency synthesizer and 89C51 frequency modulation transmitter where one-chip computer control, have recommended the phase locking to surround performance of the integrated circuit (BU2618FV ) and typical application. Having introduced BA1404 finally, BA1404 is that few frequency modulation which Japan ROHM Company produces launches one of the integrated circuits. It make three-dimensional tone, FM modulate with RF enlarging function integrate at one chip making. This text has expounded the fact in detail that has structure making up and operation principle that three-dimensional tone used extensively launches integrated circuit BA1404 frequently , provide the typical application circuit.

Key works:Dual Tone Multiple frequencyDTMF);phase-lockedloop(PLL);MT8888;FM stereo transmitter