This book covers topics discussed in courses on signals and networks, for example, continuous-time and discrete-time signal analysis, network analysis, transmission lines, and elementary analogue and digital filter design. The principles of circuit and signal theory are used to introduce the reader to the two main areas of signal processing - spectral analysis and filter design. Problems are included at the end of each chapter. The text has been aimed at advanced undergraduate and graduate students of electronic engineering, and students interested in continuous and discrete systems and networks.