Labarai - Antenna Mai Helical: Zaɓin da ya dace don Rarraba Zagaye na Broadband

AEriya Mai Karkacemisali ne na misali na eriya ta waya, wadda aka siffanta ta da tsarinta mai siffar karkace. Eriya ce mai saurin yaɗuwa wacce ta dace da madannin VHF da UHF.

Eriya mai amfani da iska tana aiki a kan kewayon mita tsakanin 30 MHz zuwa 3 GHz, galibi tana rufe madannin VHF da UHF.

Ginawa da Ka'idojin Aiki na Eriya Mai Karfe

Ana samar da Eriya Mai Karkace-karkace ta hanyar naɗe jagora zuwa siffar karkace sannan a haɗa shi da jirgin ƙasa ta hanyar layin ciyarwa. Tare da tsari mai sauƙi, yana samar da raƙuman ruwa masu zagaye kuma ana amfani da su sosai a cikin sadarwa ta waje kamar tsarin jigilar tauraron ɗan adam.

Hoton da ke sama yana nuna tsarin Eriya Mai Karfe da ake amfani da shi don sadarwa ta tauraron dan adam. Irin waɗannan eriya galibi suna buƙatar isasshen sararin shigarwa a waje.

Eriya Mai Karkace ta ƙunshi na'urar haɗa waya mai kauri ta tagulla ko bututu mai siffar helix, tana aiki tare da jirgin ƙasa mai faɗi na ƙarfe. An haɗa ƙarshen helix ɗin da mai jagoran tsakiya na kebul na coaxial, yayin da mai jagoran waje yana haɗe da jirgin ƙasa.

Hoton da ke sama yana nuna tsarin Eriya Mai Karfe, tare da cikakken bayani game da sassanta.

Ana ƙayyade halayen hasken wutar lantarki na Eriya Mai Karkace-karkace ta hanyar diamita na helix, tazara tsakanin juyawa (fitilar), da kusurwar juyawa.

An bayyana kusurwar siffa a matsayin kusurwar da ke tsakanin tangent zuwa helix da kuma jirgin sama na yau da kullun zuwa ga axis na helix, kuma an bayar da ita ta hanyar:

Ina:

•D shine diamita na helix

•S shine sautin (tazara tsakanin tsakiya da tsakiya tsakanin juyawar da ke kusa)

•α shine kusurwar filin wasa

Yanayin Aiki

Antennas na karkace suna aiki a manyan hanyoyi guda biyu:

• Yanayin Al'ada (wanda kuma aka sani da yanayin radiation mai lanƙwasa)

• Yanayin Axial (wanda kuma aka sani da yanayin ƙarewa ko yanayin hasken haske)

An bayyana kowane yanayi dalla-dalla a ƙasa.

A yanayin radiation na yau da kullun, filin da aka haskaka yana tsaye a kan axis na helix, kuma raƙuman da aka haskaka suna da'ira a zagaye. Ana samun wannan yanayin ne lokacin da girman helix ɗin ya yi ƙanƙanta idan aka kwatanta da tsawon tsayi. A wannan yanayin, ana iya ɗaukar halayen radiation na eriya ta helical a matsayin haɗin eriya ta dipole mai gajeren lokaci da eriya ta madauki.

Hoton da ke sama yana nuna tsarin hasken wutar lantarki na Eriya Mai Karkace-karkace da ke aiki a yanayin da aka saba.

Ana ƙayyade wannan yanayin ta hanyar diamita na helix D da kuma tazara tsakanin juyawar S. Rashin kyawun wannan yanayin aiki ya haɗa da ƙarancin ingancin radiation da kuma ƙaramin bandwidth; saboda haka, ba kasafai ake amfani da shi a aikace-aikace na zahiri ba.

Yanayin Axial

A yanayin radiation na axial, filin da aka haskaka yana nuna halayen wuta na ƙarshe tare da axis na helix, kuma raƙuman da aka haskaka suna da zagaye ko kusan zagaye. Ana samun wannan yanayin lokacin da aka ƙara kewayen helix zuwa tsari na tsawon rai ɗaya (λ) kuma tazara tsakanin juyawa shine kusan λ/4. A ƙarƙashin waɗannan yanayi, tsarin radiation yana da faɗi tare da axis tare da halayen alkibla, kuma lobes na gefe suna bayyana a kusurwoyi da suka karkace daga axis.

Hoton da ke sama yana nuna tsarin hasken wutar lantarki na Eriya Mai Karkace da ke aiki a yanayin axial.

Idan an tsara eriya don raƙuman da ke kewaye da hannun dama (RHCP), ba za ta karɓi raƙuman da ke kewaye da hannun hagu (LHCP) ba, haka nan kuma akasin haka. Wannan yanayin aiki yana da sauƙin aiwatarwa kuma ana amfani da shi sosai a aikace-aikace masu amfani.

Babban fa'idodin Antenna na Karkace sune kamar haka:

• Tsarin tsari mai sauƙi kuma mai sauƙin ƙira

• Babban jagora

• Faɗin bandwidth

• Mai iya raba tsakanin layukan da'ira

• Ya dace da madaurin HF da VHF

Manyan aikace-aikacen Eriya Mai Karkace sune kamar haka:

• Ana amfani da eriya ɗaya tilo mai siffar helical ko jerin su don watsawa da karɓar siginar VHF

•Ana amfani da shi sosai a tsarin sadarwa na tauraron dan adam da kuma na'urar bincike mai zurfi

• An yi amfani da shi a cikin hanyoyin sadarwa tsakanin makamai masu linzami na ballistic, tauraron dan adam, da tashoshin ƙasa

•Ana amfani da shi wajen kafa sadarwa tsakanin Wata da Duniya

•Haka kuma yana taka muhimmiyar rawa a aikace-aikacen ilmin taurari na rediyo