晶體諧振器的定義

晶(jing)體(ti)(ti)諧(xie)振(zhen)(zhen)(zhen)器(qi)就是指產(chan)生諧(xie)振(zhen)(zhen)(zhen)頻(pin)(pin)率(lv)的(de)電(dian)子(zi)(zi)元件(jian)，無源晶(jing)體(ti)(ti)生產(chan)廠家(jia)，常用(yong)的(de)分(fen)為石英(ying)晶(jing)體(ti)(ti)諧(xie)振(zhen)(zhen)(zhen)器(qi)和陶(tao)瓷(ci)諧(xie)振(zhen)(zhen)(zhen)器(qi).起(qi)產(chan)生頻(pin)(pin)率(lv)的(de)作用(yong)，具有(you)(you)穩(wen)定(ding)，抗干擾性能良好的(de)特點，廣泛應用(yong)于(yu)各(ge)種電(dian)子(zi)(zi)產(chan)品中，石英(ying)晶(jing)體(ti)(ti)諧(xie)振(zhen)(zhen)(zhen)器(qi)的(de)頻(pin)(pin)率(lv)精度(du)要高于(yu)陶(tao)瓷(ci)諧(xie)振(zhen)(zhen)(zhen)器(qi)，無源晶(jing)體(ti)(ti)現(xian)貨(huo)，但(dan)成本也(ye)比陶(tao)瓷(ci)諧(xie)振(zhen)(zhen)(zhen)器(qi)高. 諧(xie)振(zhen)(zhen)(zhen)器(qi)重要起(qi)頻(pin)(pin)率(lv)控制的(de)作用(yong)，所有(you)(you)電(dian)子(zi)(zi)產(chan)品涉及頻(pin)(pin)率(lv)的(de)發(fa)射(she)和接收都需要諧(xie)振(zhen)(zhen)(zhen)器(qi)。

目前諧(xie)振器的類型按(an)照(zhao)外(wai)形可以分為直(zhi)插式和貼片式兩中。

石(shi)英(ying)晶(jing)體(ti)(ti)俗稱水晶(jing)，成分SIO2，是重(zhong)要的(de)壓(ya)電(dian)(dian)材料(liao)，其主要特(te)征是其原子(zi)或分子(zi)有規律排列，反(fan)映在(zai)宏觀(guan)上是外形(xing)的(de)對稱性(xing)。在(zai)電(dian)(dian)場的(de)作用下，晶(jing)體(ti)(ti)內部產生(sheng)應力(li)而形(xing)變，從而產生(sheng)機械振(zhen)動，獲得(de)特(te)定的(de)頻(pin)率(lv)，利用它的(de)這種逆壓(ya)電(dian)(dian)效(xiao)應特(te)性(xing)來**石(shi)英(ying)晶(jing)體(ti)(ti)諧振(zhen)器。石(shi)英(ying)由于具備天然(ran)的(de)品質因子(zi)“Q”，這使得(de)晶(jing)體(ti)(ti)能在(zai)整個工(gong)作溫(wen)度和電(dian)(dian)壓(ya)范(fan)圍內都保(bao)持很高的(de)準確度和頻(pin)率(lv)穩定性(xing)。

晶體的壓電效應

石(shi)英(ying)晶(jing)(jing)(jing)體(ti)的(de)(de)(de)壓(ya)(ya)電(dian)(dian)(dian)(dian)(dian)效應：若在(zai)石(shi)英(ying)晶(jing)(jing)(jing)體(ti)的(de)(de)(de)兩(liang)個電(dian)(dian)(dian)(dian)(dian)極上(shang)加(jia)(jia)一(yi)電(dian)(dian)(dian)(dian)(dian)場，無源晶(jing)(jing)(jing)體(ti)價格，晶(jing)(jing)(jing)片(pian)(pian)(pian)就(jiu)會(hui)產(chan)生(sheng)(sheng)機(ji)械變(bian)(bian)形(xing)。反之(zhi)，若在(zai)晶(jing)(jing)(jing)片(pian)(pian)(pian)的(de)(de)(de)兩(liang)側施加(jia)(jia)機(ji)械壓(ya)(ya)力(li)，則在(zai)晶(jing)(jing)(jing)片(pian)(pian)(pian)相應的(de)(de)(de)方(fang)向(xiang)上(shang)將產(chan)生(sheng)(sheng)電(dian)(dian)(dian)(dian)(dian)場，這(zhe)(zhe)種物理現象(xiang)稱(cheng)為(wei)壓(ya)(ya)電(dian)(dian)(dian)(dian)(dian)效應。注意，這(zhe)(zhe)種效應是可逆的(de)(de)(de)。如果在(zai)晶(jing)(jing)(jing)片(pian)(pian)(pian)的(de)(de)(de)兩(liang)極上(shang)加(jia)(jia)交變(bian)(bian)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)，晶(jing)(jing)(jing)片(pian)(pian)(pian)就(jiu)會(hui)產(chan)生(sheng)(sheng)機(ji)械振(zhen)(zhen)動，同(tong)時晶(jing)(jing)(jing)片(pian)(pian)(pian)的(de)(de)(de)機(ji)械振(zhen)(zhen)動又會(hui)產(chan)生(sheng)(sheng)交變(bian)(bian)電(dian)(dian)(dian)(dian)(dian)場。在(zai)一(yi)般(ban)情況下，晶(jing)(jing)(jing)片(pian)(pian)(pian)機(ji)械振(zhen)(zhen)動的(de)(de)(de)振(zhen)(zhen)幅(fu)和交變(bian)(bian)電(dian)(dian)(dian)(dian)(dian)場的(de)(de)(de)振(zhen)(zhen)幅(fu)非常微小，但當外加(jia)(jia)交變(bian)(bian)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)的(de)(de)(de)頻(pin)率為(wei)某一(yi)特定值時，振(zhen)(zhen)幅(fu)明顯加(jia)(jia)大(da)，無源晶(jing)(jing)(jing)體(ti)，比其(qi)他頻(pin)率下的(de)(de)(de)振(zhen)(zhen)幅(fu)大(da)得多，這(zhe)(zhe)種現象(xiang)稱(cheng)為(wei)壓(ya)(ya)電(dian)(dian)(dian)(dian)(dian)諧(xie)(xie)(xie)振(zhen)(zhen)，它(ta)(ta)與LC回(hui)路的(de)(de)(de)諧(xie)(xie)(xie)振(zhen)(zhen)現象(xiang)十分相似(si)。它(ta)(ta)的(de)(de)(de)諧(xie)(xie)(xie)振(zhen)(zhen)頻(pin)率與晶(jing)(jing)(jing)片(pian)(pian)(pian)的(de)(de)(de)切(qie)割方(fang)式、幾何形(xing)狀、尺寸等(deng)有關。

貼片(pian)晶(jing)體諧(xie)振器(qi)(SMD)

晶(jing)(jing)體(ti)(ti)諧振(zhen)(zhen)器（SMD）也稱貼片無(wu)(wu)(wu)源(yuan)晶(jing)(jing)振(zhen)(zhen)，是利(li)用(yong)石英晶(jing)(jing)體(ti)(ti)的(de)壓(ya)電(dian)(dian)效應的(de)一(yi)種被(bei)動(dong)元器件。給石英晶(jing)(jing)體(ti)(ti)加上電(dian)(dian)壓(ya)的(de)話(hua)，晶(jing)(jing)體(ti)(ti)(壓(ya)電(dian)(dian)體(ti)(ti))會發(fa)生變形，從(cong)而振(zhen)(zhen)動(dong)產(chan)生接近其固有振(zhen)(zhen)動(dong)數的(de)穩定(ding)且高精(jing)度的(de)頻率。無(wu)(wu)(wu)源(yuan)晶(jing)(jing)振(zhen)(zhen)就是石英晶(jing)(jing)體(ti)(ti)諧振(zhen)(zhen)器的(de)別稱，主(zhu)要用(yong)在各種電(dian)(dian)子線(xian)路(lu)中起產(chan)生頻率的(de)作(zuo)用(yong)。無(wu)(wu)(wu)源(yuan)晶(jing)(jing)振(zhen)(zhen)是有2個(ge)引(yin)腳(jiao)的(de)無(wu)(wu)(wu)極性元件，需要借助于(yu)時鐘電(dian)(dian)路(lu)才能產(chan)生振(zhen)(zhen)蕩信號(hao)，自身無(wu)(wu)(wu)法振(zhen)(zhen)蕩起來(lai)。