Flashcards
Amplitude Modulation
Cards in this deck (22)
- 1Define modulationThe process where information is superimposed upon a RF carrier wave
- 2Define modulating waveThe waveform of the original intelligence
(The AF) - 3Define carrier waveThe EM wave used to carry the modulating wave
- 4Define modulated waveThis is the waveform that is transmitted
(Created by encoding the modulating waveform onto the carrier wave) - 5Define Amplitude Modulation (AM)The method in which the amplitude of the modulated wave is varied in accordance with the amplitude of the modulating wave
- 6If the amplitude of the transmission stays the same is is said to have a...?Constant envelope
- 7If the amplitude of the transmission varies in a repetitive manner is is said to have a...?Periodic envelope
- 8Define LSBLower side band
- 9Define USBUpper side band
- 10Define (fm)Modulating frequency
- 11Define (fc)Frequency carrier
- 12Define AM transmission bandwidth?The difference in Hertz between the lowest and highest frequency components of the complex waveform
- 13How would one work out the transmission bandwidth?BW = 2 x fm
- 14Define depth of modulationIndicates a measure of how much the modulating wave affects the carrier wave, the resultant waveform and the frequency spectrum
- 15Define double side band (DSB)The method of operating in which both bands of frequencies are transmitted equally.
- 16How would you work out the depth of modulation?Depth = Peak AF/Peak RF x100 = %
(80% is good) - 17What is the speech frequency range?300Hz - 3400Hz (3.4kHz)
- 18Define erect sideband?The higher the RF the higher the AF
- 19Define inverted sideband?The lower the RF the higher the AF
- 203 DSB disadvantages?1. Waste of Tx power
2. Excessive bandwidth
3. Prone to selective fading - 21Define single side band (SSB)?One side band is completely attenuated
- 222 Disadvantages of SSB1. Carrier needs to be reinserted
2. SSB equipment must be stable
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- BigDave BigDave (Topics) Flashcards on Amplitude Modulation, created by B L on 13/02/2017.
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- B L
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