Iindaba - Iziseko ze-Antena: Iiparamitha ze-Antena eziSisiseko

Izinto ezinamaqondo obushushu okwenyani angaphezu kwe-absolute zero ziya kukhupha amandla. Ubungakanani bamandla akhutshwayo budla ngokubonakaliswa kubushushu obulinganayo be-TB, obudla ngokubizwa ngokuba bubushushu bokukhanya, obuchazwa ngolu hlobo:

I-TB bubushushu bokukhanya (ubushushu obulinganayo), i-ε yi-emissivity, i-Tm bubushushu bokwenyani be-molecular, kwaye i-Γ yi-surface emissivity coefficient enxulumene ne-polarization yamaza.

Ekubeni i-emissivity ikwisithuba [0,1], ixabiso eliphezulu elinokufikelela kulo iqondo lobushushu lokukhanya lilingana nobushushu bemolekyuli. Ngokubanzi, i-emissivity ngumsebenzi we-frequency yokusebenza, i-polarization yamandla akhutshwayo, kunye nolwakhiwo lweemolekyuli zento. Kwii-frequency ze-microwave, ii-emitters zendalo zamandla amahle ngumhlaba onobushushu obulinganayo obumalunga ne-300K, okanye isibhakabhaka kwicala le-zenith elinobushushu obulinganayo obumalunga ne-5K, okanye isibhakabhaka kwicala elithe tye elimalunga ne-100 ~ 150K.

Ubushushu bokukhanya obukhutshwa zizibane ezahlukeneyo buthintelwa yi-antenna kwaye buvela kwi-i-antennaisiphelo ngendlela yobushushu be-antenna. Ubushushu obuvela kwisiphelo se-antenna bunikwe ngokusekelwe kwifomyula engentla emva kokulinganisa ipateni yokwanda kwe-antenna. Ingabonakaliswa ngolu hlobo:

I-TA yiqondo lobushushu le-antenna. Ukuba akukho lahleko yokungafani kwaye umgca wokudlulisela phakathi kwe-antenna kunye ne-receiver awunalahleko, amandla engxolo adluliselwa kwi-receiver ngala:

I-Pr ngamandla engxolo ye-antenna, i-K yi-Boltzmann constant, kwaye i-△f yi-bandwidth.

umfanekiso 1

Ukuba umgca wokudlulisela phakathi kwe-antenna kunye ne-receiver uyalahleka, amandla engxolo ye-antenna afunyenwe kwifomyula engentla kufuneka alungiswe. Ukuba ubushushu bokwenyani bomgca wokudlulisela bufana no-T0 kubude bonke, kwaye i-attenuation coefficient yomgca wokudlulisela odibanisa i-antenna kunye ne-receiver yi-α engaguqukiyo, njengoko kubonisiwe kuMfanekiso 1. Ngeli xesha, ubushushu be-antenna obusebenzayo kwindawo yokugqibela ye-receiver bu:

Apho:

I-Ta bubushushu be-antenna kwindawo yokugqibela ye-receiver, i-TA bubushushu bengxolo ye-antenna kwindawo yokugqibela ye-antenna, i-TAP bubushushu be-antenna kwindawo yokugqibela ye-antenna kubushushu obubonakalayo, i-Tp bubushushu obubonakalayo be-antenna, i-eA bubuchule bobushushu be-antenna, kwaye i-T0 bubushushu obubonakalayo bomgca wothumelo.
Ke ngoko, amandla engxolo ye-antenna kufuneka alungiswe ukuze:

Ukuba umamkeli ngokwakhe unobushushu obuthile bengxolo u-T, amandla engxolo yenkqubo kwindawo yokugqibela kamamkeli ngala:

I-Ps ngamandla engxolo yenkqubo (kwindawo yokugqibela yomkeli), i-Ta bubushushu bengxolo ye-antenna (kwindawo yokugqibela yomkeli), i-Tr bubushushu bengxolo yomkeli (kwindawo yokugqibela yomkeli), kwaye i-Ts bubushushu bengxolo esebenzayo yenkqubo (kwindawo yokugqibela yomkeli).
Umfanekiso 1 ubonisa ubudlelwane phakathi kwazo zonke iiparameter. Ubushushu bengxolo esebenzayo kwinkqubo, ii-Ts ze-antenna kunye ne-receiver yenkqubo ye-radio astronomy, ziqala kwi-K ezimbalwa ukuya kumawaka aliqela e-K (ixabiso eliqhelekileyo limalunga ne-10K), elihluka ngohlobo lwe-antenna kunye ne-receiver kunye ne-frequency yokusebenza. Utshintsho kubushushu be-antenna kwindawo yokugqibela ye-antenna olubangelwa lutshintsho kwimitha ekujoliswe kuyo lunokuba luncinci njengeeshumi ezimbalwa ze-K.

Ubushushu be-antenna kwi-input ye-antenna nakwisiphelo se-receiver bunokwahluka ngamadigri amaninzi. Umgca wokudlulisela ubude obufutshane okanye ophantsi kwelahleko unokunciphisa kakhulu lo mahluko wobushushu ube mncinci njengeeshumi ezimbalwa zedigri.

I-RF MISOlishishini eliphambili lobuchwepheshe eligxile kwi-R&D kunyeimvelisoii-antenna kunye nezixhobo zonxibelelwano. Sizibophelele kwi-R&D, uyilo, imveliso kunye nokuthengiswa kwee-antenna kunye nezixhobo zonxibelelwano. Iqela lethu lenziwe ngoogqirha, iingcali, iinjineli eziphezulu kunye nabasebenzi abanobuchule abaphambili, abanesiseko esiqinileyo sobungcali kunye namava atyebileyo okusebenza. Iimveliso zethu zisetyenziswa kakhulu kwiindlela ezahlukeneyo zorhwebo, iimvavanyo, iinkqubo zovavanyo kunye nezinye izicelo ezininzi. Sicebisa iimveliso ezininzi ze-antenna ezisebenza kakuhle kakhulu: