Bandwidth yog lwm qhov tseem ceeb kav hlau txais xov parameter. Bandwidth piav qhia txog ntau zaus uas lub kav hlau txais xov tuaj yeem ua kom raug hluav taws xob lossis tau txais lub zog. Feem ntau, qhov xav tau bandwidth yog ib qho ntawm cov tsis siv los xaiv hom kav hlau txais xov. Piv txwv li, muaj ntau hom kav hlau txais xov nrog bandwidth me me heev. Cov kav hlau txais xov no tsis tuaj yeem siv rau hauv kev siv broadband.
Bandwidth feem ntau yog hais nyob rau hauv cov nqe lus ntawm voltage sawv yoj piv (VSWR). Piv txwv li, tus kav hlau txais xov yuav raug piav qhia tias muaj VSWR <1.5 tshaj 100-400 MHz. Daim ntawv tshaj tawm hais tias qhov kev cuam tshuam coefficient tsawg dua 0.2 thoob plaws qhov ntau zaus tau hais. Yog li ntawd, ntawm lub hwj chim xa mus rau lub kav hlau txais xov, tsuas yog 4% ntawm lub hwj chim yog reflected rov qab mus rau lub transmitter. Tsis tas li ntawd, rov poob S11 = 20 * LOG10 (0.2) = 13.98 decibels.
Thov nco ntsoov tias cov saum toj no tsis txhais hais tias 96% ntawm lub zog xa mus rau lub kav hlau txais xov nyob rau hauv daim ntawv ntawm propagated electromagnetic tawg. Lub zog poob yuav tsum tau txiav txim siab.
Tsis tas li ntawd, cov qauv hluav taws xob yuav sib txawv nrog zaus. Feem ntau, cov duab ntawm cov qauv hluav taws xob tsis radically hloov qhov zaus.
Kuj tseem muaj lwm cov qauv siv los piav qhia txog kev siv bandwidth. Qhov no tuaj yeem ua polarizing nyob rau hauv ib qho chaw. Piv txwv li, lub kav hlau txais xov polarized ncig tuaj yeem piav qhia tias muaj qhov sib piv ntawm <3 dB ntawm 1.4-1.6 GHz (tsawg dua 3 dB). Qhov chaw polarization bandwidth no yog kwv yees li ntawm cov kav hlau txais xov polarized ncig.
Bandwidth feem ntau teev nyob rau hauv nws Fractional Bandwidth (FBW). FBW yog qhov sib piv ntawm qhov ntau zaus muab faib los ntawm qhov nruab nrab zaus (siab tshaj qhov qis tshaj qhov qis tshaj). Lub "Q" ntawm tus kav hlau txais xov kuj tseem cuam tshuam rau bandwidth (siab dua Q txhais tau tias qis bandwidth thiab vice versa).
Txhawm rau muab qee qhov piv txwv ntawm bandwidth, ntawm no yog lub rooj ntawm bandwidths rau hom kav hlau txais xov. Qhov no yuav teb cov lus nug, "Dab tsi yog bandwidth ntawm dipole kav hlau txais xov?" thiab "Lub kav hlau txais xov twg muaj ntau dua bandwidth - thaj chaw lossis helix kav hlau txais xov?". Rau kev sib piv, peb muaj cov kav hlau txais xov nrog qhov nruab nrab zaus ntawm 1 GHz (gigahertz) txhua.
Bandwidths ntawm ntau lub kav hlau txais xov.
Raws li koj tuaj yeem pom los ntawm lub rooj, qhov bandwidth ntawm tus kav hlau txais xov tuaj yeem sib txawv heev. Patch (microstrip) antennas muaj bandwidth tsawg heev, thaum helical antennas muaj bandwidth loj heev.
Post lub sij hawm: Nov-24-2023
