E=MC2
Newbie level 6
amplitude modulation
i have a question about amplitude modulation. in an AM transmitter the signal and the carrier frequency are multiplied with a mixer whose output is fed to the final stage amplifier which is then fed to an antenna. right????
the frequency of the carrier is about ten times the frequency of the signal (i read this somewhere). but when both the signals are multiplied the resulting amplitude modulated signal has the frequency of the carrier and the shape resembles the signal to be transmitted.
i understand the part that the output of the mixer resembles the signal. what i dont understand is why is the frequency of the modulated signal equal to the signal of the carrier. doesnt multiplication do anything to the frequency???
and my second question is that how are two analog signals multiplied?
actually i have a communications course this semester and i want to know everything about communications from A to Z. so any book recommendations would be greatly appreciated
i have a question about amplitude modulation. in an AM transmitter the signal and the carrier frequency are multiplied with a mixer whose output is fed to the final stage amplifier which is then fed to an antenna. right????
the frequency of the carrier is about ten times the frequency of the signal (i read this somewhere). but when both the signals are multiplied the resulting amplitude modulated signal has the frequency of the carrier and the shape resembles the signal to be transmitted.
i understand the part that the output of the mixer resembles the signal. what i dont understand is why is the frequency of the modulated signal equal to the signal of the carrier. doesnt multiplication do anything to the frequency???
and my second question is that how are two analog signals multiplied?
actually i have a communications course this semester and i want to know everything about communications from A to Z. so any book recommendations would be greatly appreciated