Ii-Antenna zithumela okanye zifumana ulwazi ngokukhupha amandla e-electromagnetic. Ke ngoko, amandla kunye namandla ziiparameter eziphambili ezinxulumene nala maza e-electromagnetic, kwaye kubalulekile ukuxoxa ngazo. Amaza e-electromagnetic aquka zombini intsimi yombane kunye nentsimi ye-magnetic.
Nangaliphi na ixesha, igagasi lingachazwa ngala mavektha mabini. Umfanekiso ongezantsi ubonisa iindawo zombane kunye nemagnethi zamaza e-electromagnetic.
Kwi-electromagnetic wave, intsimi yombane ihambelana ngqo necala lokusasazeka, kwaye intsimi yemagnethi ihambelana ngqo necala lokusasazeka, ngelixa intsimi yombane kunye nemagnethi zihambelana ngqo.
Ivektha yokuNgqisha
Ivektha yePoynting ichaza amandla e-electromagnetic wave ngeyunithi yexesha ngeyunithi yendawo nangaliphi na ixesha. Yaqala ukufunyanwa nguJohn Henry Poynting ngo-1884 kwaye ibizwa ngegama lakhe.
Inkcazo: Ivektha yePoynting inika izinga lokudluliselwa kwamandla kwindawo nganye yeyunithi.
Okanye: Amandla athwalwa liza ngexesha leyunithi nganye kwindawo nganye anikwa yivektha yePoynting.
Ivektha yePoynting ibonakaliswa yiS.
Iyunithi
Iyunithi ye-SI yevektha yePoynting yi-watts ngemitha yesikwere (W/m²).
Inkcazo yeMathematika
Ivektha yePoynting ekhawulezileyo, echaza amandla anxulumene ne-electromagnetic wave, ichazwa ngolu hlobo:
aphoEyivektha yombane kwayeHyivektha ye-magnetic field intensity vector.
Ukufunyanwa kwePoynting Vector
Ukuze siqonde ngcono i-Poynting vector, makhe sifumane indlela echazwa ngayo inyathelo ngenyathelo.
Cinga nge-electromagnetic wave enqumla ummandla u-A othe nkqo ukuya kwicala lokusasazeka (othathwa njenge-X-axis). Ngexesha lexesha eliphantsi kakhulu i-dt, i-wave ihamba umgama u-dx:
aphoSyivektha yePoynting. Le equation ingentla inika amandla ngexesha leyunithi nganye kwindawo yeyunithi nangaliphi na ixesha - le yintsingiselo ebonakalayo yevektha yePoynting.
Ukuze ufunde okungakumbi ngee-antenna, nceda undwendwele:
Ixesha leposi: Meyi-15-2026
