外文翻譯--無線收發(fā)模塊

1、<p><b>　　無線收發(fā)模塊</b></p><p><b>　　導(dǎo)言</b></p><p>　　無線電的發(fā)射器件都工作于射頻，因此對器件的要求也較高，一般業(yè)余條件下很難完成制作與調(diào)試工作，而目前對于無線電技術(shù)的應(yīng)用越來越廣泛，尤其對于一些業(yè)務(wù)無線電愛好者來說，要想擁有所有高頻調(diào)試的設(shè)備幾乎是不現(xiàn)實(shí)的，因?yàn)檫@些設(shè)備價(jià)格昂貴。針對這

2、些實(shí)際情況，許多專業(yè)生產(chǎn)廠家專門生產(chǎn)了用于無線數(shù)據(jù)傳輸?shù)臒o線收發(fā)模塊，將對高頻部分的安裝與調(diào)試工作全部在專業(yè)生產(chǎn)場所內(nèi)完成，用戶只要為其提供電源和所要發(fā)送的編碼數(shù)據(jù)，就可以在接收端的數(shù)據(jù)輸出端得到發(fā)送端的原始數(shù)據(jù)，這樣就可以將無線電技術(shù)的應(yīng)用得到推廣。從目前對無線電收發(fā)模塊的應(yīng)用來看，主要可分為兩大類：調(diào)頻收發(fā)模塊和調(diào)幅收發(fā)模塊。 </p><p>　　在無線廣播、電視、通信、遙控、遙測等裝置或系統(tǒng)中,除了采用振

3、幅調(diào)制方式(AM)外,還廣泛采用頻率調(diào)制方式(FM)。下面對這兩種調(diào)制方式的主要性能進(jìn)行比較:</p><p><b>　　1.抗干擾性能</b></p><p>　　調(diào)頻FM的主要優(yōu)點(diǎn)是它的抗干擾性能強(qiáng).所謂抗干擾好,主要是指在輸入信號噪聲比(簡稱信噪比S/N)相同的條件下,調(diào)頻接收機(jī)輸出端的信噪比大于調(diào)幅接收機(jī)輸出端的信噪比。調(diào)頻比調(diào)幅制的抗干擾能力強(qiáng)的原因可從兩

4、種制式的發(fā)射信號功率大小進(jìn)行分析。調(diào)頻波的邊頻分量的功率是從載波功率中分出來的。調(diào)制系數(shù)MFM越大,其邊頻不僅數(shù)目多,且幅度增大,這意味著載波功率中轉(zhuǎn)化為邊頻功率的比例大,而調(diào)幅波的邊頻功率最大僅等于載波功率的一半(當(dāng)調(diào)制指數(shù)MAM＝1時(shí))。因此,調(diào)頻波比調(diào)幅波可以具有更大的邊頻功率,這意味著它更有能力去克服信道或機(jī)內(nèi)的噪聲和干擾。其次,可從接收信號的調(diào)解來進(jìn)行對比并分析。由于調(diào)幅信號的信息包含在已調(diào)幅信號的振幅中(振幅變化與調(diào)制信號的

5、振幅成正比),解調(diào)用的包絡(luò)檢波(也稱振幅檢波)器無法抑制寄生調(diào)幅干擾；而調(diào)頻信號的信息則包含在高頻振蕩的瞬時(shí)頻率變化上,因此,干擾引起的寄生調(diào)幅可通過限幅器(或用有限幅作用的比例鑒頻器)去掉。因此,不管從發(fā)射信號的邊頻功率還是從接收信號的解調(diào)進(jìn)行分析,調(diào)頻制的抗干擾性能均優(yōu)于調(diào)幅制。</p><p><b>　　2.占用的頻帶寬度</b></p><p>　　由于寬帶

6、調(diào)頻系統(tǒng)占用的頻帶寬,調(diào)頻只適宜在超短波以上頻段（30Hz－30GHz）使用.對于中、長波頻段（中波：1000-100m，長波10－1 km）,則采用調(diào)幅或單邊帶調(diào)制方式。</p><p><b>　　3.發(fā)射機(jī)的功率</b></p><p>　　調(diào)頻制發(fā)射機(jī)發(fā)射的調(diào)頻載波的瞬時(shí)頻率是隨調(diào)制信號變化的調(diào)頻波為等幅波,它的最大功率等于平均功率;而調(diào)幅制發(fā)射機(jī)發(fā)射的是調(diào)幅

7、信號,當(dāng)MAM=1時(shí),最大發(fā)射功率等于平均功率(載波功率)的4倍.若調(diào)幅發(fā)射機(jī)與調(diào)頻發(fā)射機(jī)的末級采用同一型號的功率管,均按最大功率估算,則調(diào)頻發(fā)射機(jī)發(fā)射出的功率是調(diào)幅發(fā)射機(jī)發(fā)射的平均功率的4倍。</p><p>　　4.對調(diào)幅發(fā)射機(jī)功率放大管的要求苛刻</p><p>　　調(diào)幅發(fā)射波是隨調(diào)制信號的幅度而變化的,這就對放大管的反向耐壓有較高的要求,宜采用擊穿電壓更高的管子,否則管子易被擊穿.

8、而調(diào)頻發(fā)射機(jī)是工作在等幅狀態(tài)下的,管子不易被擊穿。</p><p><b>　　5.生產(chǎn)成本比較</b></p><p>　　生產(chǎn)調(diào)頻系列器件其調(diào)試過程相當(dāng)復(fù)雜,所以需要配備綜參測試儀、屏蔽室等昂貴的生產(chǎn)調(diào)試設(shè)備，調(diào)試設(shè)備的穩(wěn)定性直接決定產(chǎn)品的性能，還需要專業(yè)的技術(shù)工人。而生產(chǎn)調(diào)幅器件相對來說要方便許多,所以生產(chǎn)調(diào)頻產(chǎn)品的門檻要遠(yuǎn)遠(yuǎn)高于生產(chǎn)調(diào)幅產(chǎn)品,因此兩者的生產(chǎn)成本

9、相差一倍以上。通過以上對兩者的性能及成本的介紹，網(wǎng)友必對兩者的情況有所了解，目前被廣泛運(yùn)用的是調(diào)幅形式的收發(fā)組件，由于其性價(jià)比較高，同時(shí)生產(chǎn)也較為方便，因此對一些要求不是太高的場合來說，都采用了這種模式，因此本文中也重點(diǎn)對這種模塊進(jìn)行介紹。</p><p><b>　　無線發(fā)射模塊</b></p><p>　　DF數(shù)據(jù)發(fā)射模塊的工作頻率為315M，采用聲表諧振器SAW

10、穩(wěn)頻，頻率穩(wěn)定度極高，當(dāng)環(huán)境溫度在－25～＋85度之間變化時(shí)，頻飄僅為3ppm/度。特別適合多發(fā)一收無線遙控及數(shù)據(jù)傳輸系統(tǒng)。聲表諧振器的頻率穩(wěn)定度僅次于晶體，而一般的LC振蕩器頻率穩(wěn)定度及一致性較差，即使采用高品質(zhì)微調(diào)電容，溫差變化及振動(dòng)也很難保證已調(diào)好的頻點(diǎn)不會發(fā)生偏移。</p><p>　　DF發(fā)射模塊未設(shè)編碼集成電路，而增加了一只數(shù)據(jù)調(diào)制三極管Q1,這種結(jié)構(gòu)使得它可以方便地和其它固定編碼電路、滾動(dòng)碼電路及單

11、片機(jī)接口，而不必考慮編碼電路的工作電壓和輸出幅度信號值的大小。比如用PT2262或者SM5262等編碼集成電路配接時(shí)，直接將它們的數(shù)據(jù)輸出端第17腳接至DF數(shù)據(jù)模塊的輸入端即可。</p><p>　　DF數(shù)據(jù)模塊具有較寬的工作電壓范圍3～12V，當(dāng)電壓變化時(shí)發(fā)射頻率基本不變,和發(fā)射模塊配套的接收模塊無需任何調(diào)整就能穩(wěn)定地接收。當(dāng)發(fā)射電壓為3V時(shí)，空曠地傳輸距離約20～50米，發(fā)射功率較小，當(dāng)電壓5V時(shí)約100～2

12、00米，當(dāng)電壓9V時(shí)約300～500米，當(dāng)發(fā)射電壓為12V時(shí)，為最佳工作電壓，具有較好的發(fā)射效果。當(dāng)電壓大于l2V時(shí)功耗增大，有效發(fā)射功率不再明顯提高。不同的電路參數(shù)，有不同的發(fā)射功率及發(fā)射距離，要想獲得較好的發(fā)射效果，必須接上天線，天線最好選用25厘米長的導(dǎo)線，遠(yuǎn)距離傳輸時(shí)最好能夠豎立起來，因?yàn)闊o線電信號傳輸時(shí)受很多因素的影響，所以一般實(shí)用距離只有標(biāo)稱距離的一半甚至更少，這點(diǎn)需要開發(fā)時(shí)注意。</p><p>　

13、　DF數(shù)據(jù)模塊采用ASK方式調(diào)制，以降低功耗，當(dāng)數(shù)據(jù)信號停止時(shí)發(fā)射電流降為零，數(shù)據(jù)信號與DF發(fā)射模塊輸入端可以用電阻或者直接連接而不能用電容耦合，否則DF發(fā)射模塊將不能正常工作。數(shù)據(jù)電平應(yīng)接近DF數(shù)據(jù)模塊的實(shí)際工作電壓，以獲得較高的調(diào)制效果。</p><p>　　DF發(fā)射模塊最好能垂直安裝在主板的邊緣，應(yīng)離開周圍器件5mm以上，以免受分布參數(shù)影響。DF模塊的傳輸距離與調(diào)制信號頻率及幅度，發(fā)射電壓及電池容量，發(fā)射天

14、線，接收機(jī)的靈敏度，收發(fā)環(huán)境有關(guān)。一般在開闊區(qū)最大發(fā)射距離約800米，在有障礙的情況下，距離會縮短，由于無線電信號傳輸過程中的折射和反射會形成一些死區(qū)及不穩(wěn)定區(qū)域，不同的收發(fā)環(huán)境會有不同的收發(fā)距離。這一點(diǎn)對于使用者來說必須注意，筆者在利用這類模塊進(jìn)行應(yīng)用時(shí)，曾出現(xiàn)過這樣的情況，這里把他介紹給大家，希望能給在這方面應(yīng)用的網(wǎng)友啟到一定的參考：我們在為一家棋牌房設(shè)計(jì)無線呼叫系統(tǒng)時(shí)，選用的是1500米的發(fā)射模塊（很多廠家都是這樣標(biāo)識的，實(shí)際運(yùn)用

15、時(shí)還是要根據(jù)具體的環(huán)境來試驗(yàn)。）這種模塊我們在室外空曠處曾試驗(yàn)過，在500米處可以正常接收，然而運(yùn)用在這里時(shí)，相隔5個(gè)房間后就無法接收，實(shí)際距離大約在30米左右，這個(gè)環(huán)境的情況為：樓層高度為2.6米，所有的發(fā)射器件均安裝于封閉的包箱內(nèi)。為了達(dá)到可靠的呼叫功能，我們增加了兩級中繼器進(jìn)行信號放大后才實(shí)現(xiàn)功能，這里所說的中繼器就是我們網(wǎng)站上介紹的大功率無線信號轉(zhuǎn)發(fā)器。以上例子說明，這種無線收發(fā)器件直線傳輸性能較</p><

16、p><b>　　無線接收模塊</b></p><p><b>　　１超再生檢波接收器</b></p><p>　　超再生檢波電路實(shí)際上是一個(gè)受間歇振蕩控制的高頻振蕩器，這個(gè)高頻振蕩器采用電容三點(diǎn)式振蕩器，振蕩頻率和發(fā)射器的發(fā)射頻率相一致。而間歇振蕩又是在高頻振蕩的振蕩過程中產(chǎn)生的，反過來又控制著高頻振蕩器的振蕩與間歇。而間歇振蕩的頻率是由電

17、路的參數(shù)決定的（一般為１百到幾百千赫）。這個(gè)頻率選低了，電路的抗干擾性能較好，但接收靈敏度較低，反之，頻率選高，接收靈敏度較好，但抗干擾性能變差。超再生檢波電路有很高的增益，在未收到控制信號時(shí)，由于受外界雜散信號的干擾和電路自身的熱騷動(dòng)，產(chǎn)生一種特有的噪聲，叫超噪聲，這個(gè)噪聲的頻率范圍為0.3～5kHz之間，聽起來像流水似的“沙沙”聲。在無信號時(shí)，超噪聲電平很高，經(jīng)濾波放大后輸出噪聲電壓；當(dāng)有控制信號到來時(shí)，電路諧振，超噪聲被抑制，高頻

18、振蕩器開始產(chǎn)生振蕩，輸出信號。高放電路相關(guān)元件組成超再生檢波電路，檢出的控制信號經(jīng)兩級運(yùn)放進(jìn)行放大處理后，從輸出端輸出接收到無線信號。</p><p>　　2超外差接收檢波接收器</p><p>　　超外差式接收電路的工作原理和一般的超外差式收音機(jī)的原理相同。它將接收到的信號加以放大，并和本機(jī)產(chǎn)生的等幅振蕩信號相減，產(chǎn)生一個(gè)固定頻率的中頻信號，這個(gè)中頻信號的幅度中包含有低頻調(diào)制的控制信號，

19、將這個(gè)中頻信號加以兩級或三級放大，然后進(jìn)行檢波，將中頻信號中所包含的低頻指令信息取出，就得到正確的遙控信號。由于中頻放大器設(shè)有自動(dòng)增益控制回路，因此，它的增益可以設(shè)計(jì)得很高而工作十分穩(wěn)壓，這就使得超外差接收機(jī)不論對強(qiáng)信號還是弱信號，都能做到基本相同的放大倍數(shù)，也正是因?yàn)椴捎昧酥蓄l放大器，它的信號放大倍數(shù)可以達(dá)到很大，也就使電路的接收靈敏度大大提高，一般可達(dá)到0.1mV左右，與超再生檢波電路相比，超外差式接收模塊，無論在接收靈敏度上，還是

20、選擇性上都有很大的提高，在抗干擾方面更加顯著。</p><p>　　Wireless Transceiver Modules</p><p>　　Introduction</p><p>　　Radio transmitter devices are working in the radio frequency, so the requirements of the

21、 device is higher, the general time it is very difficult to complete under the conditions of production and testing work, and at present the application of radio technology for more and more widely, especially for radio

22、enthusiasts to a number of business that, in order to have all the high-frequency testing equipment is almost unrealistic, because the equipment is very expensive. In response to these actual </p><p>　　In th

23、e wireless radio, television, communications, remote control, telemetry and other devices or systems, in addition to the use of amplitude modulation (AM), but also widely used in frequency modulation ( FM). The following

24、 two main properties of modulation compared：</p><p>　　Anti-interference capacity</p><p>　　The main advantage of FM is its strong anti-interference performance. The so-called anti-interference, a

25、nd mainly refers to the input signal-noise ratio (SNR referred to as S / N) under the same conditions, the FM receiver output signal to noise ratio large AM receiver in the output signal to noise ratio. FM than AM and st

26、rong anti-interference system can be two reasons for the launch signal power system size for analysis. FM wave edge of the power frequency component is separated from the carri</p><p>　　Occupied bandwidth<

27、;/p><p>　　FM systems as a result of broadband frequency occupied bandwidth, FM is only suitable for over FM band (30Hz-30GHz) use. For the medium and long-wave band (MW:1000-100m, long-wave 10-1 km), while the

28、use of AM or SSB Modulation.</p><p>　　Transmitter power</p><p>　　FM transmitter system launched by the instantaneous FM carrier frequency changes with the modulation signal for the FM wave-wave,

29、 and its average power equal to the maximum power; and AM transmitter system is the AM signal to launch, when the MAM = 1 when the largest transmission power equal to average power (carrier power) 4 times. If the AM tran

30、smitter and FM transmitter at the end of the introduction of the same type of power tubes, according to the maximum power is estimated that the FM tran</p><p>　　4. AM transmitter power amplifier for the dema

31、nding pipe</p><p>　　Launched wave amplitude is the amplitude modulation signal with the change, which the reverse of the zoom control a higher voltage, should adopt a higher breakdown voltage of the tube, or

32、 easily puncture the tube. And FM transmitter is the amplitude in the state, the tube can not easily be puncture.</p><p>　　5. Comparison of production costs</p><p>　　FM series production of its

33、testing device is a complex process, so the need for testing is equipped with fully mechanized Senate, shielding room of the production of expensive testing equipment, testing equipment directly determine the stability o

34、f performance, but also the needs of professional skilled workers. AM production devices are relatively easy to many, so the threshold for the production of FM products is much higher than the production of AM products,

35、therefore the difference between</p><p>　　Wireless Transmitter Module</p><p>　　DF data transmitter frequency for 315M, the use of SAW resonator frequency stabilization, high frequency stability,

36、 when the environmental temperature between -25 ~ +85 degree changes, the frequency drift of only 3ppm / °c Particularly suitable for a collection of multiple wireless re mote control and data transmission system. S

37、AW resonator frequency stability after the crystal, and general LC oscillator frequency stability and consistency of poor, even with high-quality fine-tuning capacitance,</p><p>　　DF does not have code to la

38、unch module integrated circuits, and an increase of a data modulation transistor Q1, such a structure can be easily made it, and other fixed coding circuit, a rolling code and single-chip interface circuits, without havi

39、ng to consider the work of coding circuit voltage and output value of the size range of the signal. For example, using PT2262 or SM5262 matching circuits, such as coding, the data directly to the output of their first 17

40、 feet then to DF data input modul</p><p>　　DF data module has a wide operating voltage range 3 ~ 12V, when the voltage changes in firing frequency is essentially the same, and the transmitter module of the r

41、eceiver module supporting the need for any adjustment will be able to receive stable. When the firing voltage of 3V, the open transmission distance to about 20 ~ 50 meters, less transmission power, when the voltage of 5V

42、 is about 100 ~ 200 meters, when the voltage of 9V is about 300 ~ 500 meters, when fired when the voltage of 12V for</p><p>　　DF data module using ASK modulation mode to reduce power consumption, when the da

43、ta signals to stop when the emission current zero, the data signal transmitter and DF input resistance can be used or can not be directly connected to capacitive coupling, or DF module will not be able to launch normal w

44、ork. Data DF-level data should be close to the actual operating voltage modules in order to obtain the effect of higher modulation.</p><p>　　DF preferably vertical launch modules mounted on the edge of the m

45、otherboard should be left around the device more than 5mm to the impact from the distribution of parameters. DF module transmission distance and signal frequency and amplitude modulation, firing voltage and battery capac

46、ity, transmitting antenna, receiver sensitivity, send and receive environment. Generally the largest launch in the open distance of about 800 meters, there are obstacles in the circumstances, the distance will be s</p

47、><p>　　Wireless Receiver Module</p><p>　　1 super renewable detector receiver</p><p>　　Super Renewable detector circuit is actually a by intermittent oscillation control of high-frequen

48、cy oscillator, the high-frequency oscillator using three-point capacitance oscillator, oscillation frequency and the transmitter frequency of the firing line. And intermittent oscillation is the oscillation in the high-f

49、requency oscillations generated by the process, which in turn controls the high-frequency oscillator and intermittent oscillations. And intermittent oscillation frequency is determin</p><p>　　Super heterodyn

50、e receiver demodulation receiver</p><p>　　Super heterodyne receiver circuit and the general working principle of the super heterodyne radio the same principle. Received signal will be magnified, and to gener

51、ate the local oscillation signal amplitude of the subtraction, resulting in a fixed frequency IF signal, the IF signal contains low-frequency amplitude modulation control signal to the IF signal to two or three-level amp