Ok , for AM demodulation their are 2 ways of doing it envelope/diode detection. (i.e where a diode , capacitor , and resistor is used to obtain the envelope of the AM signal )
And product detection where a local osscilation (with same frequency, and phase of the AM carrier wave ) is mix together with the incoming carrier and filtered to get the original modulated message.
My problem is I don't understand AM sidebands.
I thought when you modulate a carrier wave using a AM you are just varying the amplitude so the frequency would stay the same for the carrier wave. The bandwidth is defined as the highest frequency minus the lowest frequency but with AM the frequency is the same so you should have zero bandwidth???
Are they defining AM bandwidth as the max amplitude - min amplitude and not the traditional max frequency - min frequency ???
Either way where are these sidebands coming from ???
Unless they are talking about the upper and lower envelope that can be produced with the diode detector to be these sidebands.
Are the sidebands just the envelope of the wave???
If not then is the positive part of the wave the upper sideband (i.e the sine wave parts above the y >=0 axies )
Lower sidebands y <=0 axis )
I just am unsure where these sidebands come from???
And product detection where a local osscilation (with same frequency, and phase of the AM carrier wave ) is mix together with the incoming carrier and filtered to get the original modulated message.
My problem is I don't understand AM sidebands.
I thought when you modulate a carrier wave using a AM you are just varying the amplitude so the frequency would stay the same for the carrier wave. The bandwidth is defined as the highest frequency minus the lowest frequency but with AM the frequency is the same so you should have zero bandwidth???
Are they defining AM bandwidth as the max amplitude - min amplitude and not the traditional max frequency - min frequency ???
Either way where are these sidebands coming from ???
Unless they are talking about the upper and lower envelope that can be produced with the diode detector to be these sidebands.
Are the sidebands just the envelope of the wave???
If not then is the positive part of the wave the upper sideband (i.e the sine wave parts above the y >=0 axies )
Lower sidebands y <=0 axis )
I just am unsure where these sidebands come from???