The book presents the essential contents of high-frequency technology in a scope that is tailored to practical needs, without neglecting theoretical depth. Starting from Maxwell's equations to describe general electromagnetic phenomena, the theory of transmission lines is developed before focusing on the components of high-frequency technology for real circuit designs. The majority of the book is dedicated to the generation and propagation of electromagnetic waves, as well as transmission and reception technology in the high-frequency range. Appendices with frequently needed tools from mathematics and electrical engineering complete the book.