Click here to download documentation on the current revision of our demo for the 2018 HamSCI conference. This is a version of the phasor demo developed for this semester’s modulation course, EECS 351.
Abstract: A laboratory exercise is presented for the examination of analog signals simultaneously in the time, frequency and phasor domains, as well as demodulated audio. A simulated transmitter, transmission medium, receiver front end and in-phase/quadrature demodulator are constructed using function generators, two oscilloscopes, and RF components. In this initial exercise, the focus is on the examination of an AM signal, which students vary in modulating frequency, amplitude, depth, etc. while making guided observations of the effects on each representation. This develops experiential understanding and intuition for examination of AM signals in the 3 domains, and offers a kinesthetic demonstration of concepts typically presented as blackboard exercises. The demonstration is extensible to frequency and phase modulation and QAM, and may form the basis for a semester course in modulation. The exercise has been successfully deployed in a junior-level electrical engineering class focusing on signal modulation. This work is supported by the Electrical Engineering and Computer Science department of Case Western Reserve University, through the Robert E. Collin Radiofrequency and Communications Laboratory and the Case Amateur Radio Club, W8EDU. Educational canon, including bill of materials, setup instructions, and lab exercises for this demonstration, is available at cwrucommlab.wordpress.com.