You can use the Folding Diagram to find Alias frequencies that arise when analog signals are not sampled fast enough. Remember, digital sampling will cause alliasing if the sampled signal has frequencies higher than the Nyquist Frequency ( which is one half the sampling frequency). 4. Let's look at the situation of our 40 Hz signal sampled at 50 Hz. Follow the steps below: 4.0 3.8 3.6 3.4 3.0 28 26 sampled frequency 22 sampling rate alias frequency 20 1.8 folding froqucncy 1.6 1.4 1.2 00 0.2 04 06 1O 1. What is the Nyquist (or Folding) Frequency for this situation? fy 2. Divide the highest Frequency in the original incoming signal by the Nyquist (or Folding) Frequency: fa/f 3. Use the Folding Diagram to find the ratio of the Alias Frequency over the Nyquist (or Folding) Frequency: f/= 4. Find the Alias Frequency: fa= (f/fi) x fs =_ S. Does this Alias Frequency match what you found before in 27