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Lo spettro elettromagnetico | == Lo spettro elettromagnetico == | ||
https://upload.wikimedia.org/wikipedia/commons/thumb/f/f1/EM_spectrum.svg/1280px-EM_spectrum.svg.png | |||
https://sslimgs.xkcd.com/comics/electromagnetic_spectrum.png | https://sslimgs.xkcd.com/comics/electromagnetic_spectrum.png | ||
=== la lunghezza d'onda e la frequenza === | |||
http://www.cpdm-td.unina.it/ud/rappresentazione_e_analisi_dei_suoni/INTRODUZIONE_file/image003.gif | |||
=== atmosfera === | |||
https://upload.wikimedia.org/wikipedia/commons/a/a1/Atmospheric_electromagnetic_transmittance_or_opacity-in_italian.png | |||
== Lo spettro radio == | |||
=== Le bande === | |||
==== ITU ==== | |||
{| class="wikitable" style="text-align:center" | |||
! Band Number !! Symbols !! Frequency Range !! Wavelength Range<sup>†</sup> | |||
|- | |||
| 4 || [[Very low frequency|VLF]] || 3 to 30 kHz || 10 to 100 km | |||
|- | |||
| 5 || [[Low frequency|LF]] || 30 to 300 kHz || 1 to 10 km | |||
|- | |||
| 6 || [[Medium frequency|MF]] || 300 to 3000 kHz || 100 to 1000 m | |||
|- | |||
| 7 || [[High frequency|HF]] || 3 to 30 MHz || 10 to 100 m | |||
|- | |||
| 8 || [[Very high frequency|VHF]] || 30 to 300 MHz || 1 to 10 m | |||
|- | |||
| 9 || [[Ultra high frequency|UHF]] || 300 to 3000 MHz || 10 to 100 cm | |||
|- | |||
| 10 || [[Super high frequency|SHF]] || 3 to 30 GHz || 1 to 10 cm | |||
|- | |||
| 11 || [[Extremely high frequency|EHF]] || 30 to 300 GHz || 1 to 10 mm | |||
|- | |||
| 12 || [[Tremendously high frequency|THF]] || 300 to 3000 GHz || 0.1 to 1 mm | |||
|- | |||
|} | |||
==== Ham ==== | |||
==== Civili ==== | |||
{| class="wikitable" style="text-align:center;" | |||
|- bgcolor="#E8EAF6" | |||
| '''Banda''' || '''Utilizzo''' || '''Estensione''' | |||
|- | |||
| [[banda cittadina]] || amatoriale || 26,965 - 27,405 MHz | |||
|- | |||
| [[banda 43 MHz]] || servizi vari || 43,300 - 43,5875 MHz | |||
|- | |||
| [[Low Power Devices|LPD]] || privato LPD || 433,075 - 434,775 MHz | |||
|- | |||
| [[Low Power Devices|LPD SRD]] || privato LPD || 868,00625 - 869,99375 MHz | |||
|- | |||
| [[PMR 446]] || privato PMR446 || 446,00625 - 446,09375 MHz | |||
|- | |||
| [[PMR 446|PMR 446 digitale]] || privato PMR446 || 446,103125 - 446,196875 MHz | |||
|} | |||
==== Broadcast Audio ==== | |||
{| class="wikitable" style="text-align:center;" | |||
|- bgcolor="#E8EAF6" | |||
| '''Banda''' || '''Modulazione''' || '''Estensione''' | |||
|- | |||
| [[onde lunghe]] || AM || 153 – 279 kHz | |||
|- | |||
| [[onde medie]] || AM || 525 – 1615 kHz | |||
|- | |||
| [[onde corte]] || AM || 2310kHz - 26 MHz | |||
|- | |||
| banda radio FM || FM ||87,5 - 108 MHz | |||
|- | |||
| [[Digital Audio Broadcasting|DAB]] banda L || DQPSK || 1452 - 1492 MHz | |||
|} | |||
=== Il PNRF === | |||
http://www.mise.gov.it/index.php/it/comunicazioni/radio/pnrf-piano-nazionale-di-ripartizione-delle-frequenze | |||
== La radiocomunicazione == | |||
[[File:6a.gif]] | |||
==== AM ==== | |||
[[File:Am-modulation.png]] | |||
==== FM ==== | |||
http://www.netzener.net/images/swradio/fm-modulation.png | |||
=== Antenna === | |||
l'antenna e' '''reciproca''' | |||
==== Dipolo ==== | |||
http://www.arrl.org/images/view/Licensing__Education_/Getting_on_the_Air/ARRL0113.jpg | |||
https://upload.wikimedia.org/wikipedia/commons/thumb/d/dd/Dipole_receiving_antenna_animation_6_800x394x150ms.gif/330px-Dipole_receiving_antenna_animation_6_800x394x150ms.gif | |||
==== Verticale ==== | |||
[[File:Antenna verticale.jpg|none]] | |||
==== T-antenna ===== | |||
[[File:T antenna.svg.png|none]] | |||
[[File:T-antenna-coil-autotrafo.gif|none]] | |||
==== diagramma di radiazione ==== | |||
http://www.cisco.com/c/dam/en/us/products/collateral/wireless/aironet-antennas-accessories/prod_white_paper0900aecd806a1a3e.doc/_jcr_content/renditions/0900aecd806a1a3e_null_null_null_08_07_07-04.jpg | |||
=== Mezzo fisico === | |||
==== la radiazione elettromagnetica ==== | |||
https://www.nde-ed.org/EducationResources/CommunityCollege/RadiationSafety/Graphics/elec_mag_field.gif | |||
https://upload.wikimedia.org/wikipedia/commons/4/4c/Electromagneticwave3D.gif | |||
==== near field e far field ==== | |||
https://www.osha.gov/SLTC/radiofrequencyradiation/electromagnetic_fieldmemo/electro_01.gif | |||
==== inverse square law ==== | |||
Pr = Pt/(4*pi*r^2) | |||
https://upload.wikimedia.org/wikipedia/commons/thumb/2/28/Inverse_square_law.svg/420px-Inverse_square_law.svg.png | |||
==== Polarizzazione ==== | |||
e' l'orientamento dell'E-field | |||
http://www.cdt21.com/parts/zu/zu_12.gif | |||
===== Circolare ===== | |||
https://upload.wikimedia.org/wikipedia/commons/8/81/Circular.Polarization.Circularly.Polarized.Light_Right.Handed.Animation.305x190.255Colors.gif | |||
==== Propagazione ==== | |||
http://www.msmountain.it/varie/radio/propagazione.jpg | |||
=== Trasmettitore === | |||
[[File:Transmitter.png]] | |||
=== Ricevitore === | |||
==== TRF ==== | |||
[[File:TRF-Block-Diagram.png]] | |||
==== Supereterodina ==== | |||
http://www.netzener.net/images/swradio/Superhet-Block-Diagram.png | |||
=== DDS === |
Latest revision as of 18:51, 13 October 2017
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 Audio
Banda | Modulazione | Estensione |
onde lunghe | AM | 153 – 279 kHz |
onde medie | AM | 525 – 1615 kHz |
onde corte | AM | 2310kHz - 26 MHz |
banda radio FM | FM | 87,5 - 108 MHz |
DAB banda L | DQPSK | 1452 - 1492 MHz |
Il PNRF
La radiocomunicazione
AM
FM
Antenna
l'antenna e' reciproca
Dipolo
Verticale
T-antenna =
diagramma di radiazione
Mezzo fisico
la radiazione elettromagnetica
near field e far field
inverse square law
Pr = Pt/(4*pi*r^2)
Polarizzazione
e' l'orientamento dell'E-field
Circolare
Propagazione
Trasmettitore
Ricevitore
TRF
Supereterodina