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A sinusoidal carrier of frequency 1.5 MHz and peak amplitude 50 V is amplitude-modulated by a 10 kHz signal with modulation index 0.5. What are the frequencies of the lower and upper sidebands, in kHz?

1. 1490, 1510
2. 1510, 1490
3. 1/1490, 1/1510
4. 1/1510, 1/1490

Correct answer: 1490, 1510

Solution

The lower and upper sidebands in amplitude modulation are calculated by subtracting and adding the modulating frequency (10 kHz) from the carrier frequency (1.5 MHz). This results in lower sideband frequency of 1.5 MHz - 10 kHz = 1.490 MHz (or 1490 kHz) and upper sideband frequency of 1.5 MHz + 10 kHz = 1.510 MHz (or 1510 kHz).

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