Am Flashcards
What is Am
Amplitude modulation
The method by which the amplitude of the modulated wave is varied in sympathy with amplified of the modulating wave
What is modulation?
Is the process whereby information is superimposed upon a RF carrier wave
What’s the carrier wave?
The waveform that is used to carry the modulating wave in a unmodulated state
What is the modulating wave?
The way form of the original intelligence
If the amplitude of the transmission stays the same it is said to have a…?
Constant envelope
If the amplitude of the transmission varies in repetitive manner then it is called..?
Periodic envelope
What is a frequency spectrum?
The process of modulation produces a resultant frequency spectrum that contains a number of frequency components.
What makes the lower side band? And what makes the upper sideband?
Lower - fc+fm
Higher - fc+fm
How do you calculate the transmission bandwidth?
2 * the highest modulation frequency
What is the depth of modulation and it’s equation?
Depth of modulation indicates a measure of how much the modulating wave effects carrier wave
Peak AF voltage OVER peak RF voltage x 100
Disadvantages or a double side band
Waste of transmitter power. Excessive bandwidth.
Prone to selective fading
Disadvantages of a single sideband?
Carrier needs to be reinserted.
Equipment needs to be stable and not used in domestic broadcast
