The book "RF Power Amplifier with Output Detection" offers a comprehensive analysis of the design and implementation of a 20W RF power amplifier and an envelope detector for the frequency of 1275 MHz. It begins with an introduction that sets the context for the project and outlines the design requirements. Theoretical foundations for design in high-frequency technology are covered, with an emphasis on practical aspects. The selection of components and simulation tools is made considering the specific project requirements. The book documents the design and simulation process of both devices and explains their fundamentals. Additionally, it addresses the design of a splitter/combiner, a directional coupler, and an RF attenuator. Practical challenges encountered during the assembly are discussed, and solutions are proposed. Finally, the necessary measurements for validating the requirements and fully characterizing the designs are conducted, followed by a discussion of further application possibilities for the project.