I know that IF frequency is the difference between the incoming signal and the local oscilator frequency in a frequency synthesizer. My question is why in a frequency synthesizer we need the IF frequency>
- posted
17 years ago
IF frequency qu
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- posted
17 years ago
For a simple approach, you don't need IF. You may be able to generate the RF directly when the VCO is able to do so.
Rene
-- Ing.Buero R.Tschaggelar - http://www.ibrtses.com & commercial newsgroups - http://www.talkto.net
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- posted
17 years ago
A synthesizer doesn't need an IF ("IF frequency" is redundant -- "IF" stands for "Intermediate Frequency").
Some multi-loop synthesizers have an IF sort of thing, but by no means all.
What is the context? What raised the question in your mind?
-- Tim Wescott Wescott Design Services
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- posted
17 years ago
Because in a tuner you need to select a particular frequency for amplification and detection. You could do this with a very sharp variable-frequency bandpass filter, but this is expensive and unstable. Instead you use a very sharp FIXED-frequency bandpass filter on the IF. This also has the advantage of avoiding feedback from the tuner back to it's antenna - the input and output frequencies from the mixer are completely different.
-- Joe Legris