Image Response
Calculate local oscillator frequency, f_{LO}, and image frequency, f_{ci}, for a heterodyne receiver.
f_{LO} = | |
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f_{ci} = |
Fill out the fields, you can use SI suffixes in your numbers e.g. 10k would be 10 kilo. Capitalization matter, as 1m would be 1 milli and 1M would be 1 mega. Finally, press the "Calculate" button to get the answer.
A sketch for one of the typical situations in downconversion receivers is shown below:
Frequency translation by heterodyning with f_{LO} > f_{c} . Image response creation.
Calculations are based on the following formulas:
- for downconversion (f_{IF }< f_{c}):
- if f_{LO} > f_{c }, then f_{LO} = f_{c} + f_{IF } and f_{ci} = f_{c} + 2f_{IF };
- if f_{LO} < f_{c }, then f_{LO} = f_{c} - f_{IF } and f_{ci} = f_{c} - 2f_{IF }.
- for upconversion (f_{IF }> f_{c}):
- if f_{LO} > f_{IF }, then f_{LO} = f_{c} + f_{IF } and f_{ci} = f_{c} + 2f_{IF };
- if f_{LO} < f_{IF }, then f_{LO} = f_{IF} - f_{c } and f_{ci} = 2f_{IF} - f_{c }.