In a low-IF receiver, the RFsignal is mixed down to a non-zero low or moderate intermediate frequency, typically a few megahertz (instead of 33–40 MHz) for TV, and even lower frequencies (typically 120–130 kHz instead of 10.7–10.8 MHz or 13.45 MHz) in the case of FM radio band receivers or (455–470 kHz for) AM (MW/LW/SW) receivers. Low-IF receiver topologies have many of the desirable properties of zero-IF architectures, but avoid the DC offset and 1/f noise problems.
The use of a non-zero IF re-introduces the image issue. However, when there are relatively relaxed image and neighbouring channel rejection requirements they can be satisfied by carefully designed low-IF receivers. Image signal and unwanted blockers can be rejected by quadrature down-conversion (complex mixing) and subsequent filtering.
This technique is now widely used in the tiny FM receivers incorporated into MP3 players and mobile phones and is becoming commonplace in both analog and digital TV receiver designs. Using advanced analog- and digital signal processing techniques, cheap, high quality receivers using no resonant circuits at all are now possible.
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receiver, this, article, does, cite, sources, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, news, newspapers, books, scholar, jstor, december, 2009, learn, when, remove, thi. This article does not cite any sources Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Low IF receiver news newspapers books scholar JSTOR December 2009 Learn how and when to remove this message In a low IF receiver the RF signal is mixed down to a non zero low or moderate intermediate frequency typically a few megahertz instead of 33 40 MHz for TV and even lower frequencies typically 120 130 kHz instead of 10 7 10 8 MHz or 13 45 MHz in the case of FM radio band receivers or 455 470 kHz for AM MW LW SW receivers Low IF receiver topologies have many of the desirable properties of zero IF architectures but avoid the DC offset and 1 f noise problems The use of a non zero IF re introduces the image issue However when there are relatively relaxed image and neighbouring channel rejection requirements they can be satisfied by carefully designed low IF receivers Image signal and unwanted blockers can be rejected by quadrature down conversion complex mixing and subsequent filtering This technique is now widely used in the tiny FM receivers incorporated into MP3 players and mobile phones and is becoming commonplace in both analog and digital TV receiver designs Using advanced analog and digital signal processing techniques cheap high quality receivers using no resonant circuits at all are now possible This electronics related article is a stub You can help Wikipedia by expanding it vte This article related to radio is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Low IF receiver amp oldid 1044909396, wikipedia, wiki, book, books, library,
