This book examines the new and important technology of asymmetric passive components for miniaturized microwave passive circuits. The asymmetric design methods and ideas set forth by the author are groundbreaking and have not been treated in previous works. Readers discover how these design methods reduce the circuit size of microwave integrated circuits and are also critical to reducing the cost of equipment such as cellular phones, radars, antennas, automobiles, and robots. An introductory chapter on the history of asymmetric passive components, which began with asymmetric ring hybrids first described by the author, sets the background for the book. It lays a solid foundation with a chapter examining microwave circuit parameters such as scattering, ABCD, impedance, admittance, and image. A valuable feature of this chapter is a conversion table between the various circuit matrices characterizing two-port networks terminated in arbitrary impedances. The correct conversion has also never been treated in previous works. Next, the author sets forth a thorough treatment of asymmetric passive component design, which covers the basic and indispensable elements for integration with other active or passive devices, including: Asymmetric ring hybrids Asymmetric branch-line hybrids Asymmetric three-port power dividers and N-way power dividers Asymmetric ring hybrid phase shifters and attenuators Asymmetric ring filters and asymmetric impedance transformers With its focus on the principles of circuit element design, this is a must-have graduate-level textbook for students in microwave engineering, as well as a reference for design engineers who want to learn the new and powerful design method for asymmetric passive components.