1996 - 2016
BSEE - KB3UON
RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ...
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This frequency conversion calculator takes the input frequency band and converts it to output upper and lower sidebands.
If frequency (spectral) inversion occurs, a message is place above the Lower Sideband area.
If frequency folding occurs, a message is placed next to the LSB "Lower" frequency area.
Numerical inputs are not error trapped, but some warning messages are provided. You can ignore them at your own peril.
Calculated values do not change until the "Calculate" button is clicked.
Please click this link for an explanation of Frequency (Spectral) Inversion.
To the right is an illustration of Frequency Folding within the output band. Frequency folding occurs when the local oscillator lies within the input band. Note how the Input Band frequency block has a graded fill pattern, with the lower frequencies being darker and higher frequencies being lighter.
Notice what your get when you begin calculating the mixer difference frequencies (I will use increments of 10, and units do not matter):
Of course this is an undesirable condition because from 100 to 140 there are two different frequencies that generate the same output frequency. Where this scheme might be allowable is when the input band is broken in to a series of smaller sections (using bandpass filters), along with a fixed LO.
|Related Pages on RF Cafe
- Spectral (Frequency) Inversion
- RF System Cascade Budget Calculation
- Example of System Cascade
- Frequency Modulation
- Frequency Modulation Fundamentals
- Mixer & Frequency Discriminators EW&RH
- Mixer Image Frequency
- Frequency Conversion Calculator
- A Graphical Approach to Mixer Spurious Analysis
- Mixer, Converter, Modulator & Transceiver Design
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