Ma antenna amatumiza kapena kulandira chidziwitso potulutsa mphamvu yamagetsi. Chifukwa chake, mphamvu ndi mphamvu ndi zinthu zofunika kwambiri zomwe zimagwirizanitsidwa ndi mafunde amagetsi awa, ndipo ndikofunikira kuzikambirana. Mafunde amagetsi amakhala ndi mphamvu yamagetsi komanso mphamvu yamagetsi.
Nthawi iliyonse, mafunde amatha kufotokozedwa ndi ma vector awiriwa. Chithunzi chomwe chili pansipa chikuwonetsa zigawo zamagetsi ndi maginito za mafunde amagetsi.
Mu mafunde amagetsi, mphamvu yamagetsi imakhala yolunjika ku mbali ya kufalikira, ndipo mphamvu yamagetsi nayonso imakhala yolunjika ku mbali ya kufalikira, pomwe mphamvu yamagetsi ndi mphamvu yamagetsi zimakhala zolunjika ku ina ndi ina.
Vekitala Yoyang'ana
Vektori ya Poynting imafotokoza mphamvu ya mafunde a electromagnetic pa unit time pa unit area nthawi iliyonse. Inayamba kupangidwa ndi John Henry Poynting mu 1884 ndipo imatchedwa dzina lake.
Tanthauzo: Vekitala ya Poynting imapereka liwiro la kusamutsa mphamvu pa gawo lililonse.
Kapenanso: Mphamvu yomwe imanyamulidwa ndi mafunde pa nthawi ya unit pa dera la unit imaperekedwa ndi vekitala ya Poynting.
Vekitala ya Poynting imasonyezedwa ndiS.
Chigawo
Chigawo cha SI cha vekitala ya Poynting ndi ma watts pa mita imodzi (W/m²).
Kufotokozera Masamu
Vekitala ya Poynting yomwe imachitika nthawi yomweyo, yomwe imafotokoza mphamvu yogwirizana ndi mafunde amagetsi, imafotokozedwa motere:
kutiEndi vector ya mphamvu yamagetsi ndiHndi vector ya mphamvu ya maginito.
Kuchokera kwa Poynting Vector
Kuti timvetse bwino vekitala ya Poynting, tiyeni tipeze mawonekedwe ake pang'onopang'ono.
Taganizirani za mafunde amagetsi omwe amadutsa dera A lomwe lili lolunjika ku mbali yofalikira (yotengedwa ngati X-axis). Pa nthawi yochepa kwambiri ya dt, mafundewo amayenda mtunda wa dx:
kutiSndi vekitala ya Poynting. Equation yomwe ili pamwambapa imapereka mphamvu pa nthawi ya unit pa dera la unit nthawi iliyonse - iyi ndi tanthauzo lenileni la vekitala ya Poynting.
Kuti mudziwe zambiri zokhudza ma antenna, chonde pitani ku:
Nthawi yotumizira: Meyi-15-2026
