Passive Band Pass Lim Covtuaj yeem ua los ntawm kev sib txuas ua ke ib lub lim dej qis nrog lub lim dej siab
Passive Band Pass Filter tuaj yeem siv los cais lossis lim tawm qee qhov zaus uas nyob hauv ib pawg lossis ntau zaus. Qhov kev txiav tawm zaus los yog ƒc taw tes hauv qhov yooj yim RC passive lim tuaj yeem raug tswj kom raug siv tsuas yog ib qho resistor hauv series nrog cov tsis muaj polarized capacitor, thiab nyob ntawm seb txoj kev twg nyob ib puag ncig lawv txuas, peb tau pom tias yog Low Pass lossis High Pass lim tau txais.
Ib qho yooj yim siv rau cov hom kev lim dej tsis zoo no yog nyob rau hauv daim ntawv thov suab nrov lossis cov circuits xws li hauv cov suab nrov crossover lim lossis pre-amplifier tone tswj. Qee lub sij hawm nws yog ib qho tsim nyog tsuas yog hla qee qhov ntau zaus uas tsis pib ntawm 0Hz, (DC) lossis xaus rau ntawm qee qhov siab zaus taw tes tab sis nyob hauv qee qhov ntau lossis ntau zaus, nqaim lossis dav.
Los ntawm kev sib txuas lossis "cascading" ua ke ib zaug Low Pass Filter circuit nrog High Pass Filter circuit, peb tuaj yeem tsim lwm hom passive RC lim uas hla ib qho kev xaiv lossis "band" ntawm zaus uas tuaj yeem nqaim lossis dav thaum attenuating tag nrho cov sab nraud ntawm qhov no. Hom tshiab ntawm kev lim dej tsis zoo no ua rau muaj qhov kev xaiv ntau zaus uas paub tias feem ntau yog Band Pass Filter lossis BPF luv luv.
Tsis zoo li cov lim dej qis uas tsuas yog hla cov cim ntawm qhov tsawg zaus lossis siab dhau lim uas dhau cov cim ntawm ntau zaus ntau dua, Band Pass Lim hla cov cim hauv qee qhov "band" lossis "kis" ntawm zaus yam tsis muaj kev cuam tshuam cov teeb liab tawm tswv yim lossis qhia lub suab nrov ntxiv. Qhov band ntawm zaus no tuaj yeem yog qhov dav thiab feem ntau hu ua cov lim Bandwidth.
Bandwidth feem ntau txhais tau tias yog qhov ntau zaus uas muaj nyob nruab nrab ntawm ob lub ntsiab lus ntu ntu ntu ntu (ƒc), uas yog 3dB hauv qab qhov siab tshaj plaws los yog lub siab ncov thaum attenuating lossis tsis muaj zog rau lwm tus sab nraud ntawm ob lub ntsiab lus.
Tom qab ntawd rau kev sib kis ntau zaus, peb tuaj yeem txhais lo lus "bandwidth", BW raws li qhov sib txawv ntawm qhov kev txiav tawm qis dua (ƒcLOWER) thiab qhov siab dua qhov txiav tawm zaus (ƒcHIGHER) cov ntsiab lus. Hauv lwm lo lus, BW = ƒH - ƒL. Kom meej meej rau lub lim hla dhau los ua haujlwm kom raug, qhov kev txiav tawm ntawm qhov tsawg dhau lim yuav tsum siab tshaj qhov txiav tawm zaus rau lub lim dej siab.
Qhov "zoo tagnrho" Band Pass Lim kuj tuaj yeem siv los cais lossis lim tawm qee qhov zaus uas nyob hauv ib pawg ntawm cov zaus, piv txwv li, tshem tawm suab nrov. Band pass lim feem ntau paub tias yog cov lim dej thib ob, (ob-ncej) vim tias lawv muaj "ob" reactive tivthaiv, lub capacitors, nyob rau hauv lawv cov qauv Circuit Court. Ib tug capacitor nyob rau hauv qis pass Circuit Court thiab lwm capacitor nyob rau hauv high pass circuit.
Lub Bode Plot lossis zaus teb nkhaus saum toj no qhia tau hais tias cov yam ntxwv ntawm band pass lim. Ntawm no lub teeb liab yog attenuated ntawm tsawg zaus nrog cov zis nce nyob rau hauv ib tug nqes hav ntawm +20dB/Decade (6dB/Octave) kom txog rau thaum lub zaus mus txog rau lub "tso txiav-tawm" point ƒL. Ntawm qhov zaus no cov zis voltage yog dua 1 / √2 = 70.7% ntawm cov tswv yim teeb liab tus nqi lossis -3dB (20 * log (VOUT / VIN)) ntawm cov tswv yim.
Cov zis txuas ntxiv ntawm qhov nce siab tshaj plaws kom txog thaum nws mus txog qhov "sab saum toj txiav tawm" taw tes ƒH qhov twg cov zis txo qis ntawm tus nqi ntawm -20dB / Xyoo caum (6dB / Octave) attenuating ib qho teeb meem siab. Lub ntsiab lus ntawm qhov tso zis ntau tshaj plaws yog feem ntau qhov geometric txhais tau tias ntawm ob -3dB tus nqi ntawm qhov qis thiab sab sauv txiav tawm thiab hu ua "Centre Frequency" lossis "Resonant Peak" tus nqi ƒr. Qhov no geometric txhais tau tias tus nqi yog xam raws li ƒr 2 = ƒ(UPPER) x ƒ(LOWER).
Aband pass limyog suav tias yog kev txiav txim thib ob (ob-ncej) hom lim vim nws muaj "ob" reactive Cheebtsam nyob rau hauv nws cov qauv Circuit Court, ces lub kaum sab xis theem yuav yog ob zaug ntawm qhov pom yav dhau los cov ntawv txiav txim thawj zaug, piv txwv li, 180o. Lub kaum sab xis ntawm lub teeb liab tso zis LEADS ntawm cov tswv yim los ntawm +90o mus rau qhov chaw los yog resonant zaus, ƒr taw tes yog nws dhau los ua "zero" degrees (0o) los yog "hauv-theem" thiab tom qab ntawd hloov mus rau LAG cov tswv yim los ntawm -90o raws li qhov tso zis ntau zaus.
Lub sab sauv thiab qis ntu ntu ntu ntu rau cov lim hla band tuaj yeem pom siv tib lub mis raws li qhov ntawd rau ob qhov qis thiab siab dhau lim lim, Piv txwv.
Cov chav nyob tuaj txheem nrog SMA lossis N poj niam connectors, lossis 2.92mm, 2.40mm, thiab 1.85mm connectors rau cov khoom siv ntau zaus.
Peb kuj tuaj yeem hloov kho Band Pass Lim raws li koj xav tau. Koj tuaj yeem nkag mus rau nplooj ntawv customization los muab cov kev qhia tshwj xeeb uas koj xav tau.
Post lub sij hawm: Sep-06-2022
