This book represents the culmination of several years of research into the study of slow-waves in radio frequencies and millimeter-wave frequencies, and the use of slow-wave structures for the design of transmission lines and circuits. It covers both theoretical aspects, particularly the trade-off between compactness and performance, and design methods for each of the circuits discussed. Several technologies are addressed: CMOS-BiCMOS microelectronics technology, PCB technology, and technology based on the use of nanoporous alumina membranes. All of this makes it a highly valuable resource for both master's or doctoral students, providing them with a wealth of concepts related to slow-waves in one volume, and for researchers and engineers wishing to either deepen their understanding in this field or simply utilize concepts to design high-performance and/or compact circuits.