Advances in Microwaves, Volume 2 focuses on the developments in microwave solid-state devices and circuits. This volume contains six chapters that also describe the design and applications of diplexers and multiplexers. The first chapter deals with the parameters of the tunnel diode, oscillators, amplifiers and frequency converter, followed by a simple physical description and the basic operating principles of the solid state devices currently capable of generating coherent microwave power, including transistors, harmonic generators, and tunnel, avalanche transit time, and diodes. The next chapters discuss the characteristics of cooled parametric amplifiers; effective input noise temperature, gain-bandwidth product; gain stability, shot noise and varactor heating; and design and analysis principles of varactor harmonic generators. A chapter surveys the theory, design, and applications of diplexers and multiplexers. The concluding chapter treats the numerical solution of broad classes of problems that arise in the use of TEM-mode transmission lines.