Frequency Conversion
William F. Egan · 2003
Because frequency conversion is a nonlinear process, many products, other than the desired one at the sum or difference frequency, are produced. A good estimate of the frequencies and amplitudes of these spurious products is important in designing a system to make use of the desired signal while avoiding contamination from these spurious products. A graphical method for displaying all of these outputs along with the regions that will pass through the RF and IF filters produces a picture in which the designer can clearly view the design problem and solution. Theory giving the relationships between the signal levels and the levels of the various spurious products provides another key input.