Zigawo Zosasinthika mu Ma RF Circuits
Zotsutsa, ma capacitor, ma Antena. . . . Dziwani za zigawo zosasunthika zomwe zimagwiritsidwa ntchito mu machitidwe a RF.
Machitidwe a RF si osiyana kwenikweni ndi mitundu ina ya ma circuit amagetsi. Malamulo omwewo a fizikiki amagwiranso ntchito, ndipo chifukwa chake zigawo zoyambira zomwe zimagwiritsidwa ntchito popanga ma RF zimapezekanso m'ma circuit a digito ndi ma circuit a analog otsika pafupipafupi.
Komabe, kapangidwe ka RF kamakhala ndi zovuta ndi zolinga zapadera, ndipo chifukwa chake makhalidwe ndi kagwiritsidwe ntchito ka zigawo zimafuna kuganiziridwa mwapadera tikamagwira ntchito mogwirizana ndi RF. Komanso, ma circuit ena ophatikizidwa amagwira ntchito zomwe zimasiyana kwambiri ndi machitidwe a RF—sizigwiritsidwa ntchito m'ma circuit otsika ndipo sizingamveke bwino ndi omwe alibe chidziwitso chokwanira ndi njira zopangira RF.
Nthawi zambiri timagawa zigawo monga zogwira ntchito kapena zosagwira ntchito, ndipo njira imeneyi ndi yovomerezeka mofanana mu gawo la RF. Nkhaniyi ikufotokoza zigawo zosagwira ntchito makamaka pokhudzana ndi ma RF circuits, ndipo tsamba lotsatira likufotokoza zigawo zogwira ntchito.
Ma capacitor
Capacitor yoyenera ingapereke ntchito yofanana ya chizindikiro cha 1 Hz ndi chizindikiro cha 1 GHz. Koma zigawo zake sizili zabwino kwenikweni, ndipo zabwino za capacitor zimatha kukhala zofunika kwambiri pama frequency apamwamba.
"C" ikufanana ndi capacitor yoyenera yomwe ili pakati pa zinthu zambiri za parasitic. Tili ndi kukana kosatha pakati pa ma plates (RD), kukana kwa mndandanda (RS), kukana kwa mndandanda (LS), ndi capacitance yofanana (CP) pakati pa ma PCB pads ndi ground plane (tikuganiza kuti zigawo zomangira pamwamba; zambiri zidzabwera pambuyo pake).
Chinthu chodziwika bwino kwambiri chomwe sichili bwino tikamagwiritsa ntchito ma signal a high-frequency ndi inductance. Timayembekezera kuti impedance ya capacitor ichepe mosalekeza pamene ma frequency akuwonjezeka, koma kupezeka kwa parasitic inductance kumapangitsa kuti impedance itsike pa self-resonant frequency kenako nkuyamba kuwonjezeka:
Otsutsa, ndi ena.
Ngakhale ma resistors amatha kukhala ovuta pa ma frequency apamwamba, chifukwa ali ndi series inductance, parallel capacitance, komanso capacitance yachizolowezi yogwirizana ndi ma PCB pads.
Ndipo izi zikubweretsa mfundo yofunika: mukamagwira ntchito ndi ma frequency apamwamba, zinthu za parasitic circuit zili paliponse. Kaya chinthu chotsutsa chili chosavuta kapena chabwino bwanji, chimafunikabe kupakidwa ndikugulitsidwa ku PCB, ndipo zotsatira zake zimakhala zinthu za parasitic. Zomwezo zimagwiranso ntchito ku chinthu china chilichonse: ngati chapakidwa ndikugulitsidwa ku bolodi, zinthu za parasitic zimapezeka.
Makristalo
Chofunika kwambiri cha RF ndikusintha ma signalo apamwamba kuti apereke chidziwitso, koma tisanasinthe tiyenera kupanga. Monga momwe zilili ndi mitundu ina ya ma circuits, ma crystals ndi njira yofunikira yopangira ma frequency reference okhazikika.
Komabe, pakupanga kwa digito ndi zizindikiro zosakanikirana, nthawi zambiri zimakhala kuti ma circuits okhala ndi kristalo safuna kulondola komwe kristalo ingapereke, ndipo chifukwa chake zimakhala zosavuta kukhala osasamala pankhani yosankha kristalo. Mosiyana ndi zimenezi, RF circuit ingakhale ndi zofunikira kwambiri pa ma frequency, ndipo izi sizimafuna kulondola koyambirira kwa ma frequency komanso kukhazikika kwa ma frequency.
Kusinthasintha kwa ma kristalo wamba kumakhudzidwa ndi kusintha kwa kutentha. Kusakhazikika kwa ma frequency komwe kumachitika kumabweretsa mavuto ku machitidwe a RF, makamaka machitidwe omwe adzakumana ndi kusintha kwakukulu kwa kutentha kozungulira. Chifukwa chake, makina angafunike TCXO, mwachitsanzo, oscillator ya kristalo yolipiridwa ndi kutentha. Zipangizozi zimaphatikizapo ma circuitry omwe amakwaniritsa kusintha kwa ma frequency a kristalo:
Ma antenna
Antena ndi gawo losagwira ntchito lomwe limagwiritsidwa ntchito kusintha chizindikiro chamagetsi cha RF kukhala electromagnetic radiation (EMR), kapena mosemphanitsa. Ndi zigawo zina ndi ma conductor timayesetsa kuchepetsa zotsatira za EMR, ndipo ndi ma antenna timayesetsa kukonza kupanga kapena kulandira EMR mogwirizana ndi zosowa za pulogalamuyo.
Sayansi ya ma antenna si yophweka ayi. Zinthu zosiyanasiyana zimakhudza njira yosankha kapena kupanga antenna yoyenera kugwiritsa ntchito inayake. AAC ili ndi nkhani ziwiri (dinani apa ndi apa) zomwe zimapereka chiyambi chabwino kwambiri cha malingaliro a antenna.
Ma frequency apamwamba amaphatikizidwa ndi zovuta zosiyanasiyana pakupanga, ngakhale gawo la antenna la dongosololi lingakhale losavuta pamene ma frequency akuwonjezeka, chifukwa ma frequency apamwamba amalola kugwiritsa ntchito ma antenna afupiafupi. Masiku ano ndizofala kugwiritsa ntchito "chip antenna," yomwe imagulitsidwa ku PCB ngati zigawo wamba zoyikira pamwamba, kapena antenna ya PCB, yomwe imapangidwa pophatikiza trace yopangidwa mwapadera mu kapangidwe ka PCB.
Chidule
Zigawo zina zimapezeka kwambiri mu mapulogalamu a RF okha, ndipo zina ziyenera kusankhidwa ndikugwiritsidwa ntchito mosamala kwambiri chifukwa cha khalidwe lawo losakhala labwino kwambiri la ma frequency apamwamba.
Zigawo zopanda mphamvu zimawonetsa kuyankha kosakwanira kwa ma frequency chifukwa cha kulowetsedwa kwa parasitic ndi capacitance.
Kugwiritsa ntchito ma RF kungafunike makhiristo omwe ali olondola komanso/kapena okhazikika kuposa makhiristo omwe amagwiritsidwa ntchito kwambiri m'mabwalo a digito.
Ma antenna ndi zinthu zofunika kwambiri zomwe ziyenera kusankhidwa malinga ndi makhalidwe ndi zofunikira za dongosolo la RF.
Si Chuan Keenlion Microwave ndi makina ambiri osankhidwa m'makonzedwe a narrowband ndi broadband, okhala ndi ma frequency kuyambira 0.5 mpaka 50 GHz. Amapangidwira kuti azitha kugwiritsa ntchito mphamvu yolowera ya ma watts 10 mpaka 30 mu makina otumizira mawaya 50. Mapangidwe a microstrip kapena stripline amagwiritsidwa ntchito, ndipo amakonzedwa kuti agwire ntchito bwino kwambiri.
Nthawi yotumizira: Novembala-03-2022
