This book describes the principles of operation, calibration, design and realization approaches and application of load-pull techniques in the context of PAs. It explores the topic from the basic principles of load-pull techniques through to their many interesting advancements, including passive and active techniques, high power load-pull and envelope load-pull setups with applications to amplifier, mixer and noise measurements. In addition, the book also covers waveform engineering systems, their calibration techniques and appl ications