RFI inoreva simba remagetsi risingadiwi riri mu frequency renji parinogadzirwa mukutaurirana neredhiyo.Iyo frequency range ye conduction phenomenon inotangira pa10kHz kusvika 30MHz;iyo frequency renji yeiyo radiation phenomenon iri pakati pe30MHz uye 1GHz.
Pane zvikonzero zviviri nei RFI ichifanira kutariswa: (1) Zvigadzirwa zvavo zvinofanirwa kushanda zvakajairika munzvimbo dzavanoshanda, asi nzvimbo yekushanda inowanzoperekedzwa neRFI yakaoma.(2) Zvigadzirwa zvavo hazvigone kupenya RFI kuona kuti hazvikanganise kutaurirana kweRF uko kwakakosha kune zvese hutano nekuchengetedzeka.Mutemo wakaita gadziriro yekuvimbika kweRF kutaurirana kuti ive nechokwadi chekutonga kweRFI kwemidziyo yemagetsi.
RFI inofambiswa nemwaranzi (electromagnetic waves munzvimbo yemahara) uye inofambiswa kuburikidza neiyo chiratidzo mutsara uye iyo AC simba system.
Radiation - imwe yeakanyanya kukosha masosi eRFI mwaranzi kubva kumidziyo yemagetsi ndiyo AC tambo yemagetsi.Nekuti kureba kweiyo AC tambo yemagetsi inosvika 1/4 yeinoenderana wavelength yemidziyo yedhijitari uye magetsi ekuchinja, izvi zvinoumba antenna inoshanda.
Kuitisa-Iyo RFI inoitwa nenzira mbiri pane AC simba rekupa system.Iyo yakajairika firimu (asymmetric) RFI inoitika munzira mbiri: pamutsara pasi (LG) uye isina kwayakarerekera pasi (NG), nepo differential mode (symmetric) RFI inooneka pamutsara usina kwawakarerekera (LN) muchimiro chemagetsi.
Nekukurumidza kukura kwenyika nhasi, kuwedzera uye kuwedzera simba remagetsi emagetsi rinogadzirwa.Panguva imwecheteyo, simba remagetsi rinowedzera uye rakaderera rinoshandiswa pakufambisa nekugadzirisa data, kuitira kuti ibudise simba rakawanda uye kunyange kupindira kweruzha kunoparadza zvigadzirwa zvemagetsi.Power line interference filter ndiyo imwe yenzira huru dzekusefa dzinoshandiswa kudzora RFI kubva pachigadzirwa chemagetsi kupinda (chinogona kusashanda zvakanaka) uye kubuda (kukanganisa kungava kune mamwe masisitimu kana kutaurirana kweRF).Nekudzora iyo RFI mu plug yemagetsi, iyo tambo yemagetsi sefa inodzivirira zvakanyanya kuwanda kweRFI.
Simba mutsara sefa ndiyo yakawanda chiteshi network passive chikamu, iyo yakarongedzwa mune mbiri yakaderera chiteshi sefa.Imwe network inoshandiswa kune yakajairika mode attenuation, uye imwe ndeyekusiyanisa maitiro attenuation.Iyo network inopa RF simba attenuation mu "stop bhendi" (kazhinji inodarika 10kHz) yefirita, nepo yazvino (50-60Hz) haina kuderedzwa.
Senge passive uye bilateral network, iyo yemagetsi tambo yekupindira sefa ine yakaoma switching maitiro, ayo anoenderana zvakanyanya nekwakabva uye kuremedza impedance.Iyo attenuation hunhu hwesefa inotaridzwa nekukosha kwehunhu hwekushandura.Nekudaro, munharaunda yemagetsi tambo, kwainobva uye mutoro wekudzivirira hauna chokwadi.Naizvozvo, kune yakajairwa nzira yekuona kuenderana kwesefa muindasitiri: kuyera iyo attenuation level ne50 ohm resistive sosi uye kuguma kwemutoro.Ukoshi hwakayerwa hunotsanangurwa sekurasikirwa kwekuisa (IL) kwesefa:
I..L.= 10 log * (P(l)(Ref)/P(l))
Pano P (L) (Ref) ndiro simba rinoshandurwa kubva kune chitubu kuenda kumutoro (pasina sefa);
P (L) isimba rekushandura mushure mekuisa sefa pakati pechitubu nemutoro.
Iko kurasikirwa kwekuisa kunogonawo kuratidzwa mune inotevera voltage kana yazvino reshiyo:
IL = 20 log *(V(l)(Ref)/V(l)) IL = 20 log *(I(l)(Ref)/I(l))
Pano V (L) (Ref) uye I (L) (Ref) ndiwo maitiro akayerwa asina sefa,
V (L) uye I (L) anopimwa makoshero nesefa.
Iko kurasikirwa kwekuisa, iyo inofanirwa kucherechedza, haimiriri iyo RFI attenuation performance inopiwa nesefa munzvimbo yemagetsi tambo.Munharaunda yemagetsi tambo, kukosha kwehukama kwekwakabva uye mutoro wekudzivirira unofanirwa kufungidzirwa, uye iyo yakakodzera yekusefa chimiro inosarudzwa kuita iyo yakanyanya kunaka impedance mismatch pane yega yega terminal.Iyo sefa inoenderana nekuita kweiyo terminal impedance, inova hwaro hwepfungwa ye "mismatch network".
Iyo conduction bvunzo inoda yakanyarara RF nharaunda - nhovo ganda - mutsara impedance kudzikamisa network, uye RF voltage chiridzwa (senge FM inogamuchira kana spectrum analyzer).Iyo RF nharaunda yebvunzo inofanirwa kunge iri pazasi peinodiwa yakatarwa muganho we20dB kuitira kuti uwane chaiyo bvunzo mhinduro.Iyo mutsara impedance kudzikamisa network (LISN) inodiwa kumisikidza inodiwa sosi impedance yekupinza tambo yemagetsi, inova chikamu chakakosha chechirongwa chekuyedza nekuti iyo impedance inokanganisa zvakananga kuyerwa kwemwaranzi mwero.Uye zvakare, iyo chaiyo Broadband kuyerwa kweanogamuchira zvakare yakakosha parameter yebvunzo.
Nguva yekutumira: Mar-30-2021
