Mienzaniso yeMibvunzo paKukurukurirana kweMafungu eRedhiyo
Mafungu eredhiyo rudzi rwemwaranzi yemagetsi inoshanda mukutaurirana kusina waya. Nemafrequencies anotangira pa kilohertz shoma (kHz) kusvika pa gigahertz (GHz) akati wandei, mafungu eredhiyo anoshandiswa mumhando dzakasiyana-siyana dzemashandisirwo—kubva panhepfenyuro dzeredhiyo neterevhizheni kusvika kumasisitimu ekutaurirana enharembozha. Muchinyorwa chino, tichakurukura mienzaniso yemafungu eredhiyo netsananguro dzawo kutibatsira kunzwisisa misimboti nekushandiswa kwemafungu aya muhupenyu hwezuva nezuva.
Muenzaniso Mubvunzo 1: Frequency uye Wavelength
Mubvunzo:
Nhepfenyuro yeredhiyo inotumira mafungu eredhiyo pafrequency ye100 MHz. Verenga urefu hwewavelength. (Kumhanya kwechiedza 3 x 10^8 m/s.)
Kukurukurirana:
Mafambiro (f) uye wavelength (λ) emafungu emagetsi ane chekuita nekumhanya kwechiedza (c) kuburikidza ne equation:
\[ c = f \nguva \lambda \]
Dimana:
– \( c \) = kumhanya kwechiedza (3 x 10^8 m/s)
– \( f \) = frequency (100 MHz kana 100 x 10^6 Hz)
– \( \lambda \) = kureba kwehurefu (kunowanikwa)
Kubva pa equation iri pamusoro, wavelength inogona kuverengerwa ne:
\[ \lambda = \frac{c}{f} \]
Saka:
\[ \lambda = \frac{3 \times 10^8}{100 \times 10^6} = 3 \ \text{meter} \]
Saka, kureba kwehuwandu hwe100 MHz i3 metres.
Muenzaniso Mubvunzo 2: Simba rekutumira uye Simba
Mubvunzo:
Chinotumira mawati makumi mashanu (50 watts) chinoburitsa mafungu eredhiyo nenzira inodziya (yakafanana kumativi ese). Verenga simba remafungu eredhiyo riri chinhambwe chemamita gumi kubva pachinhu chinotumira mafungu.
Kukurukurirana:
Simba (I) remafungu anoburitswa ne isotropically rinogona kuverengerwa ne:
\[ I = \frac{P}{A} \]
Dimana:
– \( P \) = simba rekutumira (50 watts)
– \( A \) = nzvimbo yepamusoro yedenderedzwa (4πr^2)
Pachinhambwe (r) = mamita gumi, nzvimbo yepamusoro yebhora ndeiyi:
\[ A = 4\pi (10)^2 = 400\pi \]
Saka:
\[ I = \frac{50}{400\pi} = \frac{1}{8\pi} \ \text{watt/m}^2 \]
Saka, simba remafungu eredhiyo ari kure nemamita gumi kubva patransmitter i \( \frac{1}{8\pi} \) watt/m².
Muenzaniso Mubvunzo 3: Bandwidth uye Kugona kweChannel
Mubvunzo:
Nzira yekutaurirana ine bandwidth ye20 MHz. Kana uchishandisa QPSK (Quadrature Phase Shift Keying) modulation, huwandu hwakanyanya hwenzira iyi hunosvika papi?
Kukurukurirana:
Kuchinja kweQPSK kune zvikamu zvina zvakasiyana, saka inogona kutumira mabhiti maviri pachiratidzo chimwe nechimwe panguva imwe chete.
Huwandu hwezviratidzo pasekondi imwe chete zvinogona kubatwa nebandwidth ye20 MHz ndeinotevera:
\[ \text{Symbol} = 20 \kawa 10^6 \ \text{symbol/second} \]
Sezvo QPSK ichitumira mabhiti maviri pachiratidzo chimwe nechimwe, kugona kana huwandu hwemabhiti pasekondi imwe neimwe (bitrate) ndeinotevera:
\[ \text{Bitrate} = 20 \times 10^6 \times 2 = 40 \ \text{Mbps} \]
Saka, kugona kukuru kwechiteshi i40 Mbps.
Muenzaniso Mubvunzo 4: Kupindira uye Kuvhiringidza
Mubvunzo:
Chinotumira redhiyo pafrequency ye101.1 MHz chinosangana nekukanganiswa kubva kune chimwe chinotumira pafrequency ye101.3 MHz. Verenga frequency inobuda.
Kukurukurirana:
Kuwanda kwekurova \( f_{beat} \) kunoitika nekuda kwemusiyano uripo pakati pema close frequencies maviri uye kunogona kuverengerwa ne:
\[ f_{beat} = |f_1 – f_2| \]
Dimana:
– \( f_1 \) = 101.1 MHz
– \( f_2 \) = 101.3 MHz
Saka:
\[ f_{beat} = |101.1 – 101.3| = | -0.2 | = 0.2 \ \mashoko{MHz} \]
Saka, frequency yekurova inobuda ndeye 0.2 MHz.
Muenzaniso Mubvunzo 5: Doppler Effect muRadio Waves
Mubvunzo:
Nhepfenyuro yeredhiyo inotumira mashoko pafrequency ye95 MHz. Ndege inosvika pachiteshi cheredhiyo nekumhanya kwe340 m/s. Verenga frequency inogamuchirwa nendege kana kumhanya kwemafungu eredhiyo kwakaenzana nekumhanya kwechiedza (3 x 10^8 m/s).
Kukurukurirana:
Doppler effect yemafungu eredhiyo inogona kuratidzwa seizvi:
\[ f_{accept} = f_{0} \left(\frac{c + v}{c}\right) \]
Dimana:
– \( f_0 \) = frequency yekutanga (95 MHz)
– \( v \) = kumhanya kwendege (340 m/s)
– \( c \) = kumhanya kwemafungu (3 x 10^8 m/s)
Saka:
\[ f_{accept} = 95 \kawa 10^6 \kuruboshwe(\frac{3 \kawa 10^8 + 340}{3 \kawa 10^8}\kurudyi) \]
\[ f_{accept} = 95 \kawa 10^6 \kuruboshwe(\frac{3 \kawa 10^8 + 3.4 \kawa 10^2}{3 \kawa 10^8}\kurudyi) \]
\[ f_{accept} \inenge 95 \kawa 10^6 \kuruboshwe(1 + \frac{3.4 \kawa 10^2}{3 \kawa 10^8}\kurudyi) \]
\[ f_{accept} \inenge 95 \kawa 10^6 \kuruboshwe(1 + 1.1333 \kawa 10^{-6}\kurudyi) \]
\[ f_{accept} \inenge 95 \kawa 10^6 \kawa 1.0000011333 \]
\[ f_{accept} \inenge 95.000107 \ \text{MHz} \]
Saka, frequency inogamuchirwa nendege iri kuuya inenge 95.000107 MHz.
Penutup
Kunzwisisa misimboti yekutanga uye mapatani ekuverenga emafungu eredhiyo kwakakosha muminda yakasiyana-siyana yeinjiniya nesainzi. Matambudziko ari pamusoro apa anopa mimwe mienzaniso yekuti fizikisi yemafungu eredhiyo inogona kushandiswa sei mumamiriro akasiyana-siyana anoshanda. Nzira yekunzwisisa kwakadzama ndeyekushandisa nguva dzose uye kuongorora mashandisirwo chaiwo emafungu eredhiyo muhunyanzvi hwekutaurirana hwatinoshandisa zuva nezuva.
