I-Polarization yenye yeempawu ezisisiseko zee-antenna. Okokuqala kufuneka siqonde i-polarization yamaza endiza. Emva koko singaxoxa ngeentlobo eziphambili ze-antenna polarization.
ukuphola okuthe ngqo
Siza kuqala ukuqonda i-polarization ye-plane electromagnetic wave.
I-planar electromagnetic wave (EM) wave ineempawu ezininzi. Eyokuqala kukuba amandla ahamba kwicala elinye (akukho ntsimi itshintshayo kwiindlela ezimbini ezilinganayo). Okwesibini, intsimi yombane kunye nentsimi yemagnethi zithe nkqo kwaye zithe nkqo. Intsimi yombane kunye nemagnethi zithe nkqo kwicala lokusasazeka kwamaza endiza. Umzekelo, cinga ngentsimi yombane ene-frequency enye (intsimi ye-E) enikwe yi-equation (1). Intsimi ye-electromagnetic ihamba kwicala le-+z. Intsimi yombane ijoliswe kwicala le-+x. Intsimi yemagnethi ikwicala le-+y.
Kwi-equation (1), qaphela uphawu: . Le yi-unit vector (ivektha yobude), ethi indawo yombane ikwicala lika-x. I-plane wave iboniswe kuMfanekiso 1.
umfanekiso 1. Umzobo wegrafikhi wentsimi yombane ehamba kwicala le-+z.
I-Polarization yi-trace kunye ne-propagation shape (contour) yentsimi yombane. Umzekelo, cinga nge-plane wave electric field equation (1). Siza kujonga indawo apho intsimi yombane i-(X,Y,Z) = (0,0,0) njengomsebenzi wexesha. Ubungakanani beli ntsimi buboniswe kuMfanekiso 2, kwiimeko ezininzi ngexesha. Intsimi iyashukuma kwi-frequency "F".
umfanekiso 2. Jonga intsimi yombane (X, Y, Z) = (0,0,0) ngamaxesha ahlukeneyo.
Intsimi yombane ibonwa kwindawo yokuqala, ijikeleza ibuyela umva nge-amplitude. Intsimi yombane isoloko ikwi-x-axis ebonisiweyo. Ekubeni intsimi yombane igcinwe kumgca omnye, le ntsimi kunokuthiwa i-linearly polarized. Ukongeza, ukuba i-X-axis ihambelana nomhlaba, le ntsimi ikwachazwa njenge-horizontal polarized. Ukuba intsimi ijoliswe kwi-Y-axis, igagasi kunokuthiwa i-vertical polarized.
Amaza ajikelezileyo ngomgca akufuneki aqondiswe kwi-axis ethe tye okanye ethe nkqo. Umzekelo, amaza ombane ane-constriction elele ecaleni komgca njengoko kubonisiwe kuMfanekiso 3 nawo angajikeleziswa ngomgca.
umfanekiso 3. I-amplitude yentsimi yombane ye-linearly polarized wave ene-trajectory eyi-engile.
Intsimi yombane ekuMfanekiso 3 ingachazwa nge-equation (2). Ngoku kukho icandelo lika-x kunye no-y lentsimi yombane. Zombini ezi nxalenye zilingana ngobukhulu.
Into enye ekufuneka uyiqaphele malunga ne-equation (2) yi-xy-component kunye ne-electronic fields kwisigaba sesibini. Oku kuthetha ukuba zombini ezi zinto zine-amplitude efanayo ngamaxesha onke.
i-polarization ejikelezayo
Ngoku masithi intsimi yombane ye-plane wave inikwe yi-equation (3):
Kule meko, izinto ze-X kunye ne-Y zingaphandle kwesigaba ngama-90 degrees. Ukuba intsimi ibonwa njengo (X, Y, Z) = (0,0,0) kwakhona njengangaphambili, intsimi yombane ngokuchasene nejika lexesha iya kuvela njengoko kuboniswe ngezantsi kuMfanekiso 4.
Umfanekiso 4. Amandla entsimi yombane (X, Y, Z) = (0,0,0) idomeyini ye-EQ. (3).
Intsimi yombane ekuMfanekiso 4 ijikeleza kwisangqa. Olu hlobo lwentsimi luchazwa njengezandi ezijikelezileyo ezijikelezileyo. Kwi-polarization ejikelezayo, kufuneka kuhlangatyezwane nale migaqo ilandelayo:
- Umgangatho we-polarization ejikelezayo
- Intsimi yombane kufuneka ibe nezinto ezimbini ezi-orthogonal (ezithe nkqo).
- Izinto ezihambelanayo zentsimi yombane kufuneka zibe ne-amplitudes elinganayo.
- Izinto ezikwi-quadrature mazibe ngama-90 degrees ngaphandle kwesigaba.
Ukuba uhamba kwisikrini seWave Figure 4, ukujikeleza kwentsimi kuthiwa kujikeleziswa ngendlela echasene newotshi kwaye kujikeleziswa ngendlela ejikelezayo ngesandla sasekunene (RHCP). Ukuba intsimi ijikeleziswa ngendlela ejikelezayo, intsimi iya kuba yi-left-handed circular polarization (LHCP).
Ukwahlulahlula kwe-elliptical
Ukuba intsimi yombane ineenxalenye ezimbini ezithe nkqo, ezingama-90 degrees ngaphandle kwesigaba kodwa zilingana ngobukhulu, intsimi iya kuba yi-elliptically polarized. Xa ucinga ngentsimi yombane yendiza ehamba kwicala le-+z, echazwe yi-Equation (4):
Indawo yenqaku apho incam yevektha yentsimi yombane iya kucingelwa khona inikwe kuMfanekiso 5
Umfanekiso 5. Intsimi yombane ye-elliptical polarization wave ekhawulezileyo. (4).
Intsimi ekuMfanekiso 5, ehamba kwicala elichasene newotshi, iya kuba yi-elliptical ngesandla sasekunene xa iphuma kwiscreen. Ukuba i-electric field vector ijikeleza kwelinye icala, intsimi iya kuba yi-elliptically polarized esebenzisa isandla sasekhohlo.
Ngaphezu koko, i-elliptical polarization ibhekisa kwi-eccentricity yayo. Umlinganiselo we-eccentricity ukuya kwi-amplitude yee-axes ezinkulu nezincinci. Umzekelo, i-eccentricity yamaza evela kwi-equation (4) yi-1/0.3 = 3.33. Amaza e-elliptically polarized achazwa ngakumbi ngokwendlela ye-major axis. I-wave equation (4) ine-axis equlathe i-x-axis. Qaphela ukuba i-major axis inokuba kuyo nayiphi na i-angle yendiza. I-angle ayifuneki ukuze ilingane ne-X, Y okanye i-Z axis. Okokugqibela, kubalulekile ukuqaphela ukuba zombini i-circular kunye ne-linear polarization ziimeko ezikhethekileyo ze-elliptical polarization. I-1.0 eccentric elliptically polarized wave yi-circularly polarized wave. Amaza e-elliptically polarized ane-eccentricity engapheliyo. Amaza e-linearly polarized.
Ukwahlulahlula kwe-antenna
Ngoku ekubeni sisazi ngeendawo ze-electromagnetic zamaza e-plane ezivuthulukileyo, i-polarization ye-antenna ichazwa ngokulula.
I-Antenna Polarization Uvavanyo lwe-antenna far-field, i-polarization yentsimi ephumayo ye-radiated. Ke ngoko, ii-antenna zihlala zidweliswa njenge-"linearly polarized" okanye "i-right-handedly polarized antennas".
Le ngcamango ilula ibalulekile kunxibelelwano lwe-antenna. Okokuqala, i-antenna e-polarized horizontal ayizukunxibelelana ne-antenna e-polarized vertical. Ngenxa ye-reciprocity theorem, i-antenna idlulisela kwaye ifumana ngendlela efanayo. Ke ngoko, ii-antenna ezi-polarized vertical zidlulisela kwaye zifumana amasimi e-polarized vertical. Ke ngoko, ukuba uzama ukuhambisa i-antenna e-polarized horizontal horizontal, akuyi kubakho kwamkelwa.
Kwimeko eqhelekileyo, kwii-antenna ezimbini ezijikeleziswe ngomgca omnye komnye nge-engile ( ), ukulahleka kwamandla ngenxa yokungahambelani kwe-polarization kuya kuchazwa yi-polarization loss factor (PLF):
Ngoko ke, ukuba ii-antenna ezimbini zine-polarization efanayo, i-engile ephakathi kwamasimi azo e-electron akhupha i-radiation ayi-zero kwaye akukho lahleko yamandla ngenxa yokungafani kwe-polarization. Ukuba i-antenna enye i-polarized ngokuthe nkqo kwaye enye i-polarized ngokuthe tye, i-engile yi-90 degrees, kwaye akukho mandla aya kudluliselwa.
QAPHELA: Ukuhambisa ifowuni phezu kwentloko yakho kwii-engile ezahlukeneyo kuchaza isizathu sokuba ulwamkelo ngamanye amaxesha lunokwandiswa. Ii-eriyali zeselfowuni zihlala zi-polarized linearly, ngoko ke ukujikeleza ifowuni kunokufana ne-polarization yefowuni, ngaloo ndlela kuphucula ulwamkelo.
I-circular polarization luphawu olunqwenelekayo lwee-antenna ezininzi. Zombini ii-antenna zi-circular polarized kwaye azinangxaki yokulahleka kwesiginali ngenxa yokungafani kwe-polarization. Ii-antenna ezisetyenziswa kwiinkqubo ze-GPS zi-right-hand polarized.
Ngoku masithi i-antenna e-polarized linearly ifumana amaza a-polarized ajikelezayo. Ngokufanayo, masithi i-antenna e-polarized circularly izama ukufumana amaza a-polarized linearly. Yintoni ebangela ukulahleka kwe-polarization?
Khumbula ukuba i-circular polarization ngokwenene ngamaza amabini a-orthogonal linearly polarized, angama-90 degrees ngaphandle kwesigaba. Ke ngoko, i-linearly polarized (LP) antenna iya kufumana kuphela i-circularly polarized (CP) wave phase component. Ke ngoko, i-LP antenna iya kuba ne-polarization mismatch loss ye-0.5 (-3dB). Oku kuyinyani nokuba i-LP antenna ijikelezwe ngayiphi na i-engile. ke ngoko:
I-Polarization loss factor ngamanye amaxesha ibizwa ngokuba yi-polarization efficiency, i-antenna mismatch factor, okanye i-antenna reception factor. Onke la magama abhekisa kwingcamango enye.
Ixesha lokuthumela: Disemba-22-2023
