Ama-antenna adlulisa noma athola ulwazi ngokukhipha amandla kagesi. Ngakho-ke, amandla namandla kuyimingcele ebalulekile ehlotshaniswa nala magagasi kagesi, futhi kubalulekile ukuxoxa ngawo. Igagasi kagesi liqukethe insimu kagesi kanye nensimu yamagnetic.
Noma nini, igagasi lingachazwa yilawa mavektha amabili. Isithombe esingezansi sibonisa izingxenye zensimu kagesi kanye neyamagnetic zegagasi likagesi.
Kumagagasi kagesi, insimu kagesi iqonde ngqo lapho kusabalala khona, kanti insimu yamagnetic nayo iqonde ngqo lapho kusabalala khona, kuyilapho amasimu kagesi namagnetic eqonde ngqo komunye nomunye.
Ivektha Yokukhomba
Ivektha yePoynting ichaza amandla wegagasi likagesi ngeyunithi ngesikhathi ngeyunithi endaweni nganoma yisiphi isikhathi. Yaqala ukutholakala nguJohn Henry Poynting ngo-1884 futhi iqanjwe ngaye.
Incazelo: Ivektha yePoynting inikeza izinga lokudluliswa kwamandla ngeyunithi ngayinye.
Ngaphandle kwalokho: Amandla athwalwa yigagasi ngesikhathi seyunithi ngayinye endaweni yeyunithi anikezwa yi-Poynting vector.
Ivektha yePoynting ichazwa ngokuthiS.
Iyunithi
Iyunithi ye-SI ye-Poynting vector ingama-watts ngemitha yesikwele (W/m²).
Ukuvezwa Kwezibalo
Ivektha ye-Poynting esheshayo, echaza amandla ahlotshaniswa negagasi le-electromagnetic, ichazwa kanje:
kuphiEiyi-vector ye-electric field intensity kanyeHiyi-vector ye-magnetic field intensity vector.
Ukutholwa kwe-Poynting Vector
Ukuze siqonde kangcono i-Poynting vector, ake sithole indlela esetshenziswa ngayo isinyathelo ngesinyathelo.
Cabanga ngegagasi likagesi elihamba ngokuvundlile endaweni u-A eqondile ukuya ohlangothini lokusabalala (elithathwa njenge-X-axis). Ngesikhathi sesikhathi esincane kakhulu u-dt, igagasi lihamba ibanga u-dx:
kuphiSyi-Poynting vector. I-equation engenhla inikeza amandla ngesikhathi seyunithi ngayinye endaweni yeyunithi nganoma yisiphi isikhathi - lokhu kuyincazelo engokoqobo ye-Poynting vector.
Ukuze ufunde kabanzi ngama-antenna, sicela uvakashele:
Isikhathi sokuthunyelwe: Meyi-15-2026
