What is Small Signal

In this chapter, microwave power attenuator and limiter theory and technological realization are presented. The chapter is divided in two sections, first section is dedicated to attenuator circuits and the second section is dedicated to power limiters circuits. Authors describe, in first section, principles characteristic and fundamentals of attenuator and detail of the most common topologies such as T-attenuator, PI-attenuator and bridged-attenuator. After a presentation of important equations needed to calculate attenuation rate provided by each of these previous cited topologies, authors present the variable attenuator based on active component (PIN diode, Transistors). In second section, authors present power limiter characteristic and fundamentals. Afterward, they present a state of arts of technological solution to design power limiter based on solid state components such as PIN diode and Schottky diodes.