From 7548ef93c09ad009cb723473034049e80779982e Mon Sep 17 00:00:00 2001 From: Tyler Perkins Date: Fri, 12 Nov 2021 14:15:01 -0500 Subject: [PATCH] Update for 12-11-21 14:15 --- tech/Modulation.wiki | 47 +++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 46 insertions(+), 1 deletion(-) diff --git a/tech/Modulation.wiki b/tech/Modulation.wiki index 697d2d4..ae64609 100644 --- a/tech/Modulation.wiki +++ b/tech/Modulation.wiki @@ -7,4 +7,49 @@ in everything from raido, to Ethernet. Bandwidth is the amount of frequencies that a signal occupies. For example, the Human voice can make frequencies from 300Hz to 3000Hz, therefore having a -bandwidth of 3000 - 300 = 2700Hz. +bandwidth of 3000 - 300 = 2700Hz. + +== Types of Modulation == + +=== CW === + +Bandwidth: 150hz + +Continuous Wave of CW is a type of signal where the pulsing of the signal +encoded information, instead of modifying the carrier signal. An example of +this is Morse code. Due to how concentrated the signal is, CW is used for +extreme ranges. + +=== AM === + +Bandwidth: 6khz (voice); 10khz (broadcast) + +Amplitude Modulation of AM is a form of modulation where the amplitude of the +signal is changed to encode information. The signal as a result will take up +space both above and below the carrier, called Upper Side Band (USB) and Lower +Side Band (LSB). + +=== SSB === + +Bandwidth: 2-3khz (voice); 500-3000hz (digital) + +Single Side Band (SSB) Is when an AM signal is encoded by only modulating one +part of the signal, and leaving the other unchanged. This allows for less +bandwidth use for the same information. + +Due to SSB concentrating the same amount of power for the signal into a +narrower portion of the signal, it is often used for long distance VHF and UHF +(see [[frequency_range]]). + +Standards have formed around SSB, and wether to use USB or LSB on different +frequencies. If < 10Mhz, LSB. Else if >= 10Mhz, USB. + +=== FM/PM === + +Bandwidth: 10-15khz (voice); 150khz (broadcast) + +Frequency Modulation (FM) and Phase Modulation (PM) are two similar types of +modulation where the signal is encoded by changing either the frequency of the +signal, or the phase of the signal. + +