車載天線
車(che)載(zai)天(tian)線(xian)是(shi)指(zhi)設(she)計(ji)安(an)裝(zhuang)在(zai)車(che)輛(liang)上(shang)的(de)移(yi)動(dong)通(tong)訊(xun)天(tian)線(xian)，最(zui)常(chang)見(jian)就(jiu)是(shi)吸(xi)盤(pan)天(tian)線(xian)。由(you)於(yu)吸(xi)盤(pan)天(tian)線(xian)安(an)裝(zhuang)擺(bai)放(fang)容(rong)易(yi)，所(suo)以(yi)在(zai)一(yi)些(xie)簡(jian)易(yi)設(she)台(tai)場(chang)合(he)常(chang)常(chang)用(yong)吸(xi)盤(pan)天(tian)線(xian)代(dai)替(ti)基(ji)地(di)天(tian)線(xian)。車(che)載(zai)天(tian)線(xian)結(jie)構(gou)上(shang)有(you)縮(suo)短(duan)型(xing)、四分之一波長、中部加感型、八分之五波長、shuangerfenzhiyibochangdengxingshidetianxian，lilunshangtamendexiaolvyicizengjia，tongyanggongzuopinduandetianxiandechangduyeyicizengjia。youyucheliangbenshenyouxiangao，jiashangguochangdetianxianzaichelianggaosuxingjinshixingchengdefengzu，guoqiaodong、進入地下車庫都是問題，所以車載天線並不是越長越好，一般要求轎車天線不超過70厘li米mi，麵mian包bao車che類lei要yao求qiu天tian線xian更geng短duan。縮suo短duan型xing天tian線xian體ti積ji小xiao巧qiao，雖sui然ran增zeng益yi不bu高gao，但dan適shi合he使shi用yong於yu需xu要yao隱yin蔽bi天tian線xian的de場chang合he。一yi般ban的de警jing用yong車che輛liang建jian議yi安an裝zhuang高gao增zeng天tian線xian，尤you其qi是shi在zai活huo動dong區qu域yu範fan圍wei比bi較jiao大da的de車che輛liang，350MHZ高增益天線多分為八分之五波長加感的形式，在距天線頂部二分之一波長距離處有一個加感線圈。400MHZpinduanshuangerfenzhiyibochangtianxianjuyoujiaogaodezengyi，tadewaiguantezhengshitianxiandezhenzishangyoulianggejiaganxianquan。bafenzhiwubochangtianxianhezhongbujiaganxingtianxianyeyoujiaogaodezengyi，qiejiagebijiaobianyi，yincidedaoguangfandeshiyong。zaizuoweilinshigudingtaitianxianshiyongdechanghekeyikaolvxuanyongzengyigaodexipantianxian，tianxiandechangdububiyouguoduoxianzhi。youyuxipantianxianshigenjuqicheshiyonghuanjingershejisuoyizaizuoweigudingshiyongshizaiqixiaxiyikuaibanjingdayu1米的金屬板（如鐵皮）會(hui)有(you)更(geng)好(hao)的(de)使(shi)用(yong)效(xiao)果(guo)。由(you)於(yu)進(jin)口(kou)原(yuan)裝(zhuang)的(de)車(che)載(zai)天(tian)線(xian)價(jia)格(ge)非(fei)常(chang)昂(ang)貴(gui)且(qie)優(you)勢(shi)不(bu)突(tu)出(chu)，所(suo)以(yi)一(yi)般(ban)都(dou)選(xuan)用(yong)國(guo)產(chan)車(che)載(zai)天(tian)線(xian)。在(zai)天(tian)線(xian)選(xuan)型(xing)階(jie)段(duan)主(zhu)要(yao)參(can)考(kao)天(tian)線(xian)的(de)外(wai)型(xing)和(he)增(zeng)益(yi)。建(jian)議(yi)選(xuan)用(yong)大(da)廠(chang)家(jia)的(de)名(ming)牌(pai)產(chan)品(pin)，他(ta)們(men)提(ti)供(gong)的(de)參(can)數(shu)真(zhen)實(shi)性(xing)比(bi)較(jiao)高(gao)，製(zhi)造(zao)工(gong)藝(yi)也(ye)有(you)保(bao)證(zheng)。如(ru)果(guo)是(shi)批(pi)量(liang)采(cai)購(gou)完(wan)全(quan)可(ke)以(yi)到(dao)專(zhuan)業(ye)天(tian)線(xian)製(zhi)造(zao)廠(chang)家(jia)按(an)使(shi)用(yong)頻(pin)段(duan)定(ding)製(zhi)，以(yi)取(qu)得(de)最(zui)佳(jia)的(de)使(shi)用(yong)效(xiao)果(guo)。
基地台天線
jiditaitianxianzaizhenggetongxunxitongzhongjuyoufeichangguanjiandezuoyong，youqishizuoweitongxunshuniudetongxintaizhan。gaozengyitianxianbudankeyizengjiawuxiandianbodefugaimianji，erqieduijieshouxinhaoyeyouyidingdefangdazuoyong，keyigenghaodejieshouweiruodeshangxingxinhao，gaishanyidongtaiyujiditaidewuxiantongxunzhiliang。yibanqingkuangxiaji
地台都選用高增益天線，對於有幹擾的情況可以按實際情況考慮加裝窄帶濾波器以減小幹擾的影響。常用的基地台
玻bo璃li鋼gang天tian線xian為wei全quan向xiang天tian線xian基ji本ben沒mei有you方fang向xiang性xing，適shi合he基ji地di台tai位wei置zhi位wei於yu通tong訊xun網wang絡luo中zhong心xin區qu域yu的de情qing況kuang。由you於yu玻bo璃li鋼gang天tian線xian安an裝zhuang容rong易yi，因yin此ci廣guang泛fan應ying用yong於yu各ge類lei基ji地di台tai站zhan。玻bo璃li鋼gang天tian線xian增zeng益yi最zui高gao可ke以yi達da到dao10db左右，增益越高天線也就越長，一般增益為5-6db增(zeng)益(yi)的(de)玻(bo)璃(li)鋼(gang)天(tian)線(xian)在(zai)長(chang)度(du)和(he)價(jia)格(ge)上(shang)比(bi)較(jiao)有(you)競(jing)爭(zheng)力(li)，製(zhi)造(zao)工(gong)藝(yi)也(ye)比(bi)較(jiao)成(cheng)熟(shu)，采(cai)用(yong)較(jiao)多(duo)。該(gai)類(lei)天(tian)線(xian)除(chu)了(le)電(dian)氣(qi)性(xing)能(neng)外(wai)，外(wai)層(ceng)玻(bo)璃(li)鋼(gang)天(tian)線(xian)罩(zhao)的(de)品(pin)質(zhi)也(ye)有(you)很(hen)大(da)的(de)差(cha)異(yi)，一(yi)些(xie)劣(lie)質(zhi)產(chan)品(pin)在(zai)風(feng)吹(chui)日(ri)曬(shai)一(yi)年(nian)後(hou)外(wai)層(ceng)玻(bo)璃(li)鋼(gang)會(hui)出(chu)現(xian)開(kai)裂(lie)的(de)情(qing)況(kuang)導(dao)致(zhi)整(zheng)條(tiao)天(tian)線(xian)報(bao)廢(fei)，一(yi)些(xie)大(da)廠(chang)名(ming)牌(pai)的(de)玻(bo)璃(li)鋼(gang)天(tian)線(xian)在(zai)品(pin)質(zhi)上(shang)更(geng)有(you)保(bao)障(zhang)。
定(ding)向(xiang)天(tian)線(xian)相(xiang)當(dang)於(yu)把(ba)多(duo)個(ge)方(fang)向(xiang)上(shang)的(de)能(neng)量(liang)集(ji)中(zhong)到(dao)一(yi)個(ge)方(fang)向(xiang)上(shang)來(lai)發(fa)射(she)，具(ju)有(you)主(zhu)方(fang)向(xiang)輻(fu)射(she)增(zeng)益(yi)高(gao)的(de)特(te)點(dian)，常(chang)用(yong)的(de)是(shi)八(ba)木(mu)天(tian)線(xian)。八(ba)木(mu)天(tian)線(xian)的(de)單(dan)元(yuan)數(shu)越(yue)多(duo)其(qi)增(zeng)益(yi)也(ye)越(yue)高(gao)，適(shi)合(he)點(dian)對(dui)點(dian)遠(yuan)距(ju)離(li)通(tong)訊(xun)和(he)位(wei)於(yu)通(tong)訊(xun)網(wang)邊(bian)緣(yuan)的(de)子(zi)台(tai)站(zhan)使(shi)用(yong)。比(bi)較(jiao)適(shi)合(he)位(wei)於(yu)偏(pian)遠(yuan)地(di)區(qu)的(de)派(pai)出(chu)所(suo)定(ding)向(xiang)與(yu)上(shang)級(ji)分(fen)局(ju)聯(lian)係(xi)之(zhi)用(yong)，使(shi)用(yong)得(de)當(dang)效(xiao)果(guo)會(hui)優(you)於(yu)玻(bo)璃(li)鋼(gang)天(tian)線(xian)。
四環陣天線的特點是承受功率大、增益高、增益方向可調，適合通訊樞紐（分局和市局以及中繼台站）使用，不過其價格比較高。四環陣天線四個發射振子方向可調，當四個振子間隔90度du安an裝zhuang時shi天tian線xian特te性xing基ji本ben為wei全quan向xiang，當dang四si個ge振zhen子zi全quan部bu安an裝zhuang在zai同tong一yi方fang向xiang時shi天tian線xian特te性xing具ju有you方fang向xiang性xing，同tong時shi在zai主zhu輻fu射she方fang向xiang增zeng益yi提ti高gao。利li用yong其qi增zeng益yi方fang向xiang可ke調tiao的de特te性xing可ke以yi更geng好hao的de適shi應ying非fei規gui則ze服fu務wu區qu。如ru果guo四si環huan陣zhen天tian線xian的de增zeng益yi不bu夠gou高gao可ke以yi考kao慮lv八ba環huan陣zhen天tian線xian，它ta的de特te性xing與yu四si環huan陣zhen類lei似si但dan提ti供gong了le更geng高gao的de增zeng益yi。一yi般ban350MHZ頻段四環陣的增益為8db（全向）/10db（定向），八環陣的增益為12db（全向）/15db(定向）。
參考網址：http://www.crtegd.com/dgz-8.asp