This book presents harmonic-balance techniques that substantially increase designer control over oscillation in autonomous circuits. These new simulation techniques have been published before in journals, but have never been explained with the pedagogical detail found here. The author provides an explanation and analysis of the main types of autonomous circuits, including push-push oscillators, coupled-oscillators, harmonic-injection dividers, and self-oscillating mixers. Techniques are also presented for the stabilization of circuits in which the oscillators are undesired. Microwave circuit designers and RF microwave graduate students will find this book to be exceptionally resourceful.