A new book from CRC Press, Networks and Devices Using Planar Transmission Lines, by Franco Di Paolo, joins practical information and physical principles for the proper functioning of planar transmission devices in one text. Chapters of the book are dedicated to the analysis of planar transmission lines and their related devices, such as directional couplers, directional filters, phase shifters, circulators and isolators. Another feature of the book is the discussion of ferrimagnetic devices, with three appendices dedicated to the theoretical aspect of ferrimagnetism. Also provided are more than 490 figures to illustrate the input-output transfer functions in a particular device and more than 500 up-to-date references.