This book describes for readers the entire, interconnected complex of theoretical and practical aspects of designing and organizing the production of various electronic devices, the general and main distinguishing feature of which is the high speed of processing and transmitting of digital signals. The authors discuss all the main stages of design - from the upper system level of the hierarchy (telecommunications system, 5G mobile communications) to the lower level of basic semiconductor elements, printed circuit boards. Since the developers of these devices in practice deal with distorted digital signals that are transmitted against a background of interference, the authors not only explain the physical nature of such effects, but also offer specific solutions as to how to avoid such parasitic effects, even at the design stage of high-speed devices.