Ithiyori ye-Antenna yeNtambo eNde: Iindidi, Imigaqo yokuSebenza kunye nezicelo zoVavanyo lwe-RF

Kwithiyori ye-antenna, ubudlelwane phakathi kobude be-antenna kunye nobude be-wavelength yokusebenza yenye yezona zinto zibalulekileyo ezichaphazela ukusebenza kwemitha. I-antenna ende yocingo ngumzekelo oqhelekileyo. Ngokungafaniyo ne-dipole emfutshane okanye i-half-wave dipole, i-antenna ende yocingo idla ngokuba nobude obungaphezulu kobude be-wavelength enye okanye yenziwe ngamacandelo amaninzi e-half-wave length.

Ngamazwi alula, ubude be-antenna ende yocingo bunokubonakaliswa ngolu hlobo:

L = nx lambda / 2

Kule ntetho, u-L bubude be-antenna, i-lambda bubude be-wavelength, kwaye u-n umele inani lamacandelo e-half-wave length. Njengoko ubude bukhula, ipateni yemitha ye-antenna iba kwicala elingaphezulu. Oku kuthetha ukuba i-antenna ende enocingo inokugxininisa amandla amaninzi kwicala elithile endaweni yokuqaqambisa ngokulinganayo kuzo zonke iindlela.

Kutheni Ubude be-Antenna Bubalulekile

Ubude be-antenna buchaphazela ngokuthe ngqo ukusasazwa kwangoku, i-impedance, i-gain kunye ne-radiation pattern. Xa i-antenna iba nde, i-current ecaleni kwentambo ayisebenzi njenge-radiator emfutshane elula. Endaweni yoko, amacandelo ahlukeneyo entambo anegalelo kwi-radiation pattern yokugqibela. Ngenxa yoko, i-antenna inokuvelisa imisebe emincinci, ii-lobes ezininzi kunye ne-directivity ephezulu.

Kwiinjineli ezisebenza ngoyilo lwe-antenna ye-RF, iinkqubo zonxibelelwano okanye ukulinganisa i-antenna, ukuqonda olu lwalamano kuluncedo. Nangona iimveliso ze-antenna ze-microwave zanamhlanje zinokusebenzisa ii-antenna ze-horn, izakhiwo ze-waveguide, ii-antenna ze-planar okanye ii-antenna ze-reflector, umgaqo osisiseko uhlala ufana: ubude be-wavelength, ulwakhiwo lomzimba kunye nokuziphatha kwemitha zidibene ngokusondeleyo.

Iintlobo ezimbini eziphambili zee-Antennas ze-Long Wire

Ii-antenna ezinde zixutyushwa rhoqo kwiindidi ezimbini: ii-antenna ezi-resonant kunye nee-antenna ezingezizo ezi-resonant.

I-antenna ende ephindaphindayo isebenza kwi-frequency apho amaza amileyo enziwa khona ecaleni komqhubi. Kule meko, ubude be-antenna bunxulumene kakhulu ne-frequency yokusebenza. Amandla ahamba kwi-antenna kwaye inxalenye yawo inokubonakaliswa, okudala ipateni ye-standing wave. Ngenxa yale ndlela yokuziphatha, ii-antenna ezinde eziphindaphindayo zihlala zithathwa njengezakhiwo zexesha kwaye zinokubonisa iimpawu zemitha ye-bidirectional.

I-antenna ende engenamsindo idla ngokuyilwa ukunciphisa ukubonakaliswa nokuxhasa ukuziphatha kwamaza okuhamba. I-antenna idla ngokupheliswa ngomthwalo ofanelekileyo ukuze amaza ahambe kwicala elinye. Oku kunceda ukunciphisa amaza amileyo kwaye kunokwenza imitha ye-antenna ilawulwe ngakumbi. Kolu hlobo lwe-antenna, ukulinganisa i-impedance kubaluleke kakhulu kuba kuchaphazela indlela amandla anikezelwa ngayo kwaye asasazwa ngayo ngokufanelekileyo.

Iphethini yeMisebe kunye neZikhokelo

Uphawu olubalulekileyo lwe-antenna ende yocingo kukuqondisa kwayo. Njengoko ubude bentambo busanda, i-antenna inokuvelisa imitha enamandla ngakumbi kumacala akhethiweyo. Nangona kunjalo, oku akuthethi ukuba uyilo luba lula rhoqo. Ucingo olude lunokuvelisa ii-side lobes ezininzi, ekufuneka ziqwalaselwe kuyilo lwenkqubo kunye novavanyo lwe-antenna.

Kwizicelo ze-RF ezisebenzayo, iinjineli kufuneka zivavanye ipateni yemitha ye-antenna, i-gain, i-polarization kunye neempawu ze-impedance. Ezi parameters zinceda ekuqinisekiseni ukuba i-antenna ifanelekile na kwiikhonkco zonxibelelwano, iinkqubo zovavanyo, iimvavanyo zelebhu okanye ezinye iindawo ze-RF.

Uqhagamshelo neRF kunye noVavanyo lweMicrowave

Nangona ii-antenna ezinde zidla ngokwaziswa njengesihloko sethiyori ye-antenna esisiseko, iingcamango ezingasemva kwazo zibalulekile nakwi-RF kunye nobunjineli be-microwave. Kuvavanyo lwee-antenna zobungcali, iinjineli zihlala zithelekisa iintlobo ezahlukeneyo ze-antenna ngokulinganisa i-gain, i-VSWR, i-directivity, i-polarization kunye ne-radiation pattern.

I-RF MISO iphuhlisa kwaye ivelise ii-antenna kunye nezixhobo zonxibelelwano zezicelo zorhwebo, zovavanyo kunye neenkqubo zovavanyo. Iimveliso ezifana nee-antenna ze-horn, ii-waveguide probes, ii-antenna ezibonisa ukukhanya, ii-antenna ze-planar kunye nezixhobo ze-microwave zisetyenziswa kakhulu ekulinganisweni kwee-antenna, uvavanyo lwe-RF kunye nophando lwenkqubo yonxibelelwano. Ukuqonda ithiyori ye-antenna esisiseko kunceda iinjineli zikhethe ii-antenna ezifanelekileyo kwaye zakhe iinkqubo zovavanyo ezinokuthenjwa ngakumbi.

Umzekelo, xa ukhetha i-antenna yovavanyo, iinjineli zinokufuna ukuqwalasela oku kulandelayo:

- Uluhlu lweefrikhwensi zokusebenza
- Inzuzo kunye nesikhokelo
- Ukwahlulahlula
- Ukuthelekiswa kwe-VSWR kunye ne-impedance
- Uzinzo lwepateni yemitha
- Ulwakhiwo loomatshini kunye neemeko zokufakelwa
- Ukuhambelana neenkqubo zokulinganisa

Ezi zinto azipheleli nje kwii-antenna ezinde. Zikwabalulekile nakwii-antenna ze-microwave horn, ii-antenna ze-waveguide kunye nezinye iimveliso ze-antenna ze-RF zobungcali.

Izicelo kunye nexabiso lobuNjineli

Ithiyori ye-antenna yocingo olude iluncedo ekuqondeni imitha ebhekisa kwicala elithile, uyilo olunxulumene nobude be-wavelength kunye nokuziphatha kwamaza okuhamba. Kumsebenzi wobunjineli bokwenyani, imigaqo efanayo ibonakala kwizakhiwo ezininzi ze-antenna, kubandakanya ii-antenna ze-V, ii-antenna ze-rhombic, ii-antenna ze-log-periodic kunye nezinye iinkqubo ze-antenna ezibhekisa kwicala elithile.

Kwizicelo ze-RF zanamhlanje kunye ne-microwave, ukusebenza kwe-antenna kufuneka kuqinisekiswe ngokulinganisa okufanelekileyo. I-antenna eyilwe kakuhle akufuneki ihlangabezane neemfuno zethiyori kuphela kodwa ikwafanele isebenze ngokuthembekileyo kwindawo yokusebenza yokwenyani. Yingakho ukulinganiswa kwe-antenna kunye novavanyo lwe-RF ziyinxalenye ebalulekileyo yophuhliso lwemveliso kunye nokuhlanganiswa kwenkqubo.

Isiphelo

I-antenna ende yingcamango ebalulekileyo kwithiyori ye-antenna. Ubude bayo, ubude bayo, imeko ye-resonance kunye nendlela yokuphelisa zonke ezi zinto zichaphazela ipateni yemitha kunye nolwalathiso. Ngokuqonda umahluko phakathi kwee-antenna ezinde ze-resonant kunye ne-non-resonant, iinjineli zinokuqonda ngcono indlela ulwakhiwo lwe-antenna oluchaphazela ngayo ukusebenza kwe-RF.

Kubathengi abasebenza ekulinganiseni i-antenna, uvavanyo lwe-microwave, iinkqubo zonxibelelwano okanye uphando lwelebhu, i-RF MISO ibonelela ngeemveliso ze-antenna kunye nenkxaso yobugcisa kwiindidi ezahlukeneyo ze-RF kunye nezicelo ze-microwave. Nxibelelana ne-RF MISO ukuze uxoxe ngemida yefrikhwensi oyifunayo, uhlobo lwe-antenna kunye neemfuno zovavanyo.