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why can't remove the Image frequency using a band-pass filter?
I've been asked to search for the reason why we can't use BPF (band-pass filter) in order to remove the effects of the Image frequency?
I've searched but couldn't find anything useful about it. I would be glad if you could help me.

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  • $\begingroup$ Your question is ambiguous. You certainly can remove an image with a bandpass filter placed before a mixer. Please show a block diagram of your proposed system, indicating where the filters are. $\endgroup$ – TimWescott Jun 27 '19 at 19:31
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You only know something is an "image frequency" because you know what the signal was like before you sampled it and reduced its bandwidth.

Do an experiment, either with real hardware or a computer simulation. Use a sampling rate of say 1000/sec and sample analog sine wave signals at 200 Hz and 800 Hz. The sampled data will be identical even though you would describe the sampled 800 Hz as an "image frequency".

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