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Question
What is the function of a bandpass filter used in a modulator for obtaining AM signal?
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Solution
The output produced by the square-law device is passed to the bandpass filter which rejects the dc and the sinusoids of frequencies wm, 2wm, and 2wc and retains the frequencies wc, wc – wm, and wc + wm. The output of the bandpass filter is an AM wave.
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