In many industrial applications, the existing constraints mandate the use of controllers of low and fixed order while, typically, modern methods of optimal control produce high order controllers. Structure and Synthesis of PID Controllers seeks to start to bridge the resultant gap and presents a novel methodology for the design of low-order controllers such as those of the P, PI and PID types. Written in a self-contained and tutorial fashion, this research monograph first develops a fundamental result, generalizing a classical stability theorem - the Hermite-Biehler Theorem - and then applies it to designing controllers that are widely used in industry. It contains material on: current techniques for PID controller design, generalization of the Hermite-Biehler theorem, stabilization of linear time-invariant plants using PID controllers, optimal design with PID controllers, robust and non-fragile PID controller design, stabilization of first-order systems with time delay, constant-gain stabilization with desired damping, constant-gain stabilization of discrete-time plants. Practitioners, researchers and graduate students should find this book a valuable source of information on cutting-edge research in the field of control.