Ob peb lub tswv yim ntawm Electromagnetic Radiation
1. Cov khoom siv hluav taws xob hluav taws xob ntau
Feem ntau hais lus, radar systems, TV thiab broadcasting systems, xov tooj cua zaus induction thiab nruab nrab cua sov cov khoom, xov tooj cua zaus thiab microwave cov khoom kho mob, ntau yam khoom siv hluav taws xob ua, kev sib txuas lus chaw nres tsheb, satellite ntiaj teb kev sib txuas lus chaw nres tsheb, cov chaw tsim hluav taws xob loj, cov khoom siv hluav taws xob thiab kev hloov pauv. , high-voltage thiab ultra-high voltage kis tau tus mob kab, subway tsheb ciav hlau thiab hluav taws xob tsheb ciav hlau, raws li zoo raws li feem ntau ntawm cov khoom siv hauv tsev, muaj peev xwm tsim tau ntau yam ntaub ntawv, frequencies, thiab intensity ntawm electromagnetic tawg qhov chaw.
2. Kev faib hluav taws xob hluav taws xob hauv cheeb tsam
Cov hluav taws xob hluav taws xob hluav taws xob feem ntau muab faib ua thaj tsam deb thiab ze- teb.
2.1 Ze ntawm thaj chaw thiab cov yam ntxwv
Ib cheeb tsam nyob rau hauv ib lub wavelength thaj tsam nyob rau hauv lub teb qhov chaw, feem ntau hu ua lub ze-field los yog sensing teb
Yingchang. Qhov chaw ze ze feem ntau muaj cov yam ntxwv hauv qab no:
Tsis muaj qhov sib npaug ntawm qhov sib txawv ntawm lub zog ntawm lub teb hluav taws xob thiab lub zog ntawm cov hlau nplaum hauv qhov chaw ze. npe: E \377H. Feem ntau, rau cov chaw hauv cheeb tsam uas muaj hluav taws xob siab thiab tsis tshua muaj tam sim no (xws li xa cov kav hlau txais xov, feeders, thiab lwm yam), cov hluav taws xob hluav taws xob muaj zog dua li cov hlau nplaum. Rau cov khoom siv hluav taws xob uas tsis tshua muaj hluav taws xob thiab siab tam sim no (xws li pwm ntawm qee yam khoom siv cua sov induction), qhov chaw sib nqus yog ntau dua li qhov hluav taws xob.
Kev siv hluav taws xob hluav taws xob hauv thaj tsam ze yog ntau dua li qhov nyob deb. Los ntawm qhov kev xav no, lub hom phiaj ntawm kev tiv thaiv electromagnetic yuav tsum nyob ze ntawm qhov chaw.
Lub electromagnetic teb siv nyob rau hauv ze-tsav sib txawv ceev ceev nrog nyob deb, uas ua rau ib tug tseem ceeb tsis sib xws nyob rau hauv qhov chaw no.
2.2 Far field thiab yam ntxwv
Lub spatial ntau yam nrog rau qhov chaw hluav taws xob ntawm qhov chaw nruab nrab thiab ib lub vojvoog dhau ib lub wavelength yog hu ua qhov chaw deb lossis hluav taws xob. Cov yam ntxwv tseem ceeb ntawm thaj chaw deb yog raws li hauv qab no:
Nyob rau hauv qhov deb, yuav luag tag nrho cov hluav taws xob hluav taws xob hluav taws xob yog hluav taws xob thiab nthuav tawm hauv daim ntawv ntawm cov hluav taws xob hluav taws xob, thiab qhov txo qis ntawm cov hluav taws xob siv hluav taws xob hauv daim teb no qeeb dua li hauv qhov induced teb.
Nyob rau hauv qhov chaw deb, muaj kev sib raug zoo ntawm lub zog hluav taws xob thiab lub zog hlau nplaum raws li hauv qab no: nyob rau hauv lub thoob ntiaj teb system ntawm units, E=377H, cov kev taw qhia ntawm hluav taws xob teb thiab magnetic teb ua hauj lwm yog perpendicular rau txhua. lwm yam, thiab ob qho tib si yog perpendicular rau cov kev taw qhia ntawm electromagnetic yoj propagation.
Qhov chaw deb yog qhov chaw tsis muaj zog, thiab nws qhov kev siv hluav taws xob electromagnetic yog me me.
2.3 Qhov tseem ceeb ntawm kev faib thaj tsam ze thiab thaj tsam deb
Feem ntau, rau qhov chaw ruaj khov hluav taws xob hluav taws xob uas tuaj yeem tsim muaj qee qhov kev siv, qhov siv hluav taws xob hauv hluav taws xob ntawm cov hluav taws xob nyob ze yog qhov siab. Yog li ntawd, peb yuav tsum tau xyuam xim ntxiv rau kev tiv thaiv ntawm ze-tsav electromagnetic hluav taws xob. Kev tiv thaiv hluav taws xob hluav taws xob nyob rau hauv qhov chaw ze yog thawj zaug thiab qhov tseem ceeb tshaj plaws rau cov neeg ua haujlwm thiab cov neeg nyob ze ntawm thaj chaw, tom qab ntawd los ntawm kev tiv thaiv ntau yam khoom siv hluav taws xob thiab hluav taws xob nyob hauv thaj tsam ze. Rau cov teb nyob deb, vim lub zog me me ntawm electromagnetic teb, qhov kev puas tsuaj rau tib neeg feem ntau me me. Hauv qhov no, qhov tseem ceeb uas peb yuav tsum xav txog yog kev tiv thaiv teeb liab. Tsis tas li ntawd, yuav tsum muaj lub tswv yim rau thaj tsam ze, uas suav nrog ntau zaus ntawm 30MHz hauv qhov luv luv mus rau 3000MHz hauv micro band uas peb nquag ntsib, nrog wavelengths ntawm 10 meters mus rau 1 meter.
