Laboratory implementation of some analog and digital modulation schemes using single circuit

In this work we present laboratory implementation of some experiments in the domain of Analog and Digital Communication. Usually different circuits are used for each experiment, and sometimes, `plug-in´ modules are used to connect and observe waveforms at different stages of the modulator. The single circuit proposed can be used to generate the three forms of amplitude modulation: standard amplitude modulation (DSB); double side band suppressed carrier (DSB-SC); single side band (SSB); and three forms of digital modulation like the amplitude shift keying (ASK); binary phase shift keying (BPSK); frequency shift keying (FSK). In addition, the same circuit is used to generate natural sampled waveform and the two-channel time division multiplexed waveform. We discuss the method and then present the experimental results.