Low IF and image frequency
时间：04-07
整理：3721RD
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Hi,
I know that low IF receivers do not need the second bandpass filter (after the LNA at the antenna side) because they don't have an image problem (not the image frequency, but rather an image noise coming from the LNA). That, in contrast to real IF receivers, which have 2 BPF's, one before the LNA, and one after it.
My question is - why?
I know that low IF receivers do not need the second bandpass filter (after the LNA at the antenna side) because they don't have an image problem (not the image frequency, but rather an image noise coming from the LNA). That, in contrast to real IF receivers, which have 2 BPF's, one before the LNA, and one after it.
My question is - why?