屏蔽層的效果為防攪擾,防電磁。
同(tong)(tong)(tong)軸(zhou)電(dian)纜(lan)(lan)從用途上(shang)分可分為基(ji)(ji)帶同(tong)(tong)(tong)軸(zhou)電(dian)纜(lan)(lan)和寬帶同(tong)(tong)(tong)軸(zhou)電(dian)纜(lan)(lan)(即網絡同(tong)(tong)(tong)軸(zhou)電(dian)纜(lan)(lan)和視頻同(tong)(tong)(tong)軸(zhou)電(dian)纜(lan)(lan))。同(tong)(tong)(tong)軸(zhou)電(dian)纜(lan)(lan)分50Ω 基(ji)(ji)帶電(dian)纜(lan)(lan)和75Ω寬帶電(dian)纜(lan)(lan)兩類。基(ji)(ji)帶電(dian)纜(lan)(lan)又分細同(tong)(tong)(tong)軸(zhou)電(dian)纜(lan)(lan)和粗同(tong)(tong)(tong)軸(zhou)電(dian)纜(lan)(lan)。基(ji)(ji)帶電(dian)纜(lan)(lan)只是用于數字傳輸,數據率(lv)可達10Mbps。
同軸電(dian)纜(lan)(lan)(lan)(Coaxial Cable)是(shi)指有兩個同心(xin)導體,而導體和屏蔽層又共用同一軸心(xin)的(de)電(dian)纜(lan)(lan)(lan)。最常見的(de)同軸電(dian)纜(lan)(lan)(lan)由絕緣資(zi)料(liao)(liao)阻隔的(de)銅(tong)線導體組成(cheng),在里(li)層絕緣資(zi)料(liao)(liao)的(de)外部是(shi)另(ling)一層環(huan)形導體及(ji)其絕緣體,然后整個電(dian)纜(lan)(lan)(lan)由聚氯乙烯(xi)或特氟綸資(zi)料(liao)(liao)的(de)護套(tao)包住。
同軸電纜首要用在(zai)微波傳輸中,這是(shi)(shi)一(yi)種(zhong)很(hen)高速的一(yi)種(zhong)數據,民(min)用較常(chang)見(jian)首要用于有線電視和網絡連接中,其(qi)最首要效果(guo)是(shi)(shi)內導(dao)體(ti)與外導(dao)體(ti)的尺度合作,以完成精確地阻抗匹配,使功率的傳輸功率到達較高的水平,這通常(chang)是(shi)(shi)針對頻率高于10MHz的信號而言。
還有一個明(ming)顯的效(xiao)果(guo),便是屏(ping)蔽(bi)外(wai)界(jie)的攪擾,使(shi)外(wai)界(jie)空間(jian)的各(ge)種雜散信號被阻隔在屏(ping)蔽(bi)層外(wai),使(shi)信號完好無失真(zhen),使(shi)數據(ju)無過錯。