Radio: Difference between revisions
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https://www.nde-ed.org/EducationResources/CommunityCollege/RadiationSafety/Graphics/elec_mag_field.gif | https://www.nde-ed.org/EducationResources/CommunityCollege/RadiationSafety/Graphics/elec_mag_field.gif | ||
https:// | https://upload.wikimedia.org/wikipedia/commons/4/4c/Electromagneticwave3D.gif | ||
==== near field e far field ==== | ==== near field e far field ==== | ||
Revision as of 15:03, 3 July 2015
Lo spettro elettromagnetico
la lunghezza d'onda e la frequenza
atmosfera
Lo spettro radio
Le bande
ITU
| Band Number | Symbols | Frequency Range | Wavelength Range† |
|---|---|---|---|
| 4 | VLF | 3 to 30 kHz | 10 to 100 km |
| 5 | LF | 30 to 300 kHz | 1 to 10 km |
| 6 | MF | 300 to 3000 kHz | 100 to 1000 m |
| 7 | HF | 3 to 30 MHz | 10 to 100 m |
| 8 | VHF | 30 to 300 MHz | 1 to 10 m |
| 9 | UHF | 300 to 3000 MHz | 10 to 100 cm |
| 10 | SHF | 3 to 30 GHz | 1 to 10 cm |
| 11 | EHF | 30 to 300 GHz | 1 to 10 mm |
| 12 | THF | 300 to 3000 GHz | 0.1 to 1 mm |
Ham
Civili
| Banda | Utilizzo | Estensione |
| banda cittadina | amatoriale | 26,965 - 27,405 MHz |
| banda 43 MHz | servizi vari | 43,300 - 43,5875 MHz |
| LPD | privato LPD | 433,075 - 434,775 MHz |
| LPD SRD | privato LPD | 868,00625 - 869,99375 MHz |
| PMR 446 | privato PMR446 | 446,00625 - 446,09375 MHz |
| PMR 446 digitale | privato PMR446 | 446,103125 - 446,196875 MHz |
Broadcast
| Banda | Utilizzo | Estensione |
| onde lunghe | radio AM | 153 – 279 kHz |
| onde medie | radio AM | 525 – 1615 kHz |
| onde corte | radio AM | 2310 kHz - 30 MHz |
| banda radio FM | radio FM | 87,5 - 108 MHz |
| DAB banda L | radio digitale | 1452 - 1492 MHz |
Il PNRF
La radiocomunicazione
Trasmettitore
Antenna
l'antenna e' reciproca
Dipolo
diagramma di radiazione
Mezzo fisico
near field e far field
inverse square law
Antenna
Ricevitore
