Demodulation or detection is the process of recovering the information carried by a modulated wave. The amplitude demodulation requirements split by application, complexity, and cost, into the two categories of synchronous and asynchronous detection. Figure 1 shows the amplitude demodulated wave at the receiver.

Figure 1: Demodulation of the modulated carrier at the receiver

The principle used in FlexTrainer for amplitude demodulation uses full-wave rectification and then low pass filtering. There is a set of 8 low pass filters in FlexTrainer. The students can select anyone of them and observe the results. Selection of just the right filter gives the desired results.

At the end of this experiment, students are questioned about effects of filter selection, carrier frequency and modulation index on the amplitude modulated wave.