Over the past decade the tremendous development of Wireless Communications has changed human life incredibly. Considerable advancement has been made in the design and architecture of communications related RF and Microwave circuits. This book is focused on special circuits dedicated to the RF level of wireless Communications. From Oscillators to Modulation and Demodulation and from Mixers to RF and Power Amplifier Circuits, the topics are presented in a sequential manner. A wealth of analysis is provided in the text alongside various worked out examples. Related problem sets are given at the end of each chapter. Basic concepts of RF Analog Circuit Design are developed in the book. Technical topics discussed in the book include: Wireless Communication System; RF Oscillators and Phase Locked Loops; Modulator and Demodulator Circuits; RF Mixers; Automatic Gain Control and Limiters; Microwave Circuits, Transmission Lines and S-Parameters; Matching networks Linear Amplifier Design and Power Amplifiers Linearization Techniques