Directional coupler and Power dividers play a valuable role in the RF field, microwave application and radar areas for measuring power level of signals, measurement, radar and other airborne equipment such as transceivers, power amplifiers, phase array, etc.It is a fundamental component of RF and microwave system and can be used for power dividing or power combining. Commonly used in antenna feeds, modulators, balanced mixers, etc. In this book we studied about simulation of power divider and directional coupler using CST MWS software which is excellent in performance and using PCB technology to fabricate to reduce the cost and ease to use in the laboratory. Basic fundamentals and observations of directional coupler and power dividers are also included in this book. Hoping this book will benefit you for further research and skills development in a microwave field. Good Luck!