The book focuses on the design of a compact and miniature RF front-end structure operating within a 2.45 GHz unlicensed ISM band for WPT applications. WPT components are composed of five essential elements: antenna, pre-filter, rectifier, post-filter and load. Emphasis will be given only on designing the antenna and filter towards the compactness feature for the WPT application. Several selected design methods are used to achieve compactness with acceptable performances. The chosen approaches are studied to occupy the compact antenna and filter structures. The proposed antennas and filters are simulated and optimized using Computer Simulation Technology (CST) based on the required performances. The optimum design is fabricated and measured in terms of the S11, radiation pattern, gain and AR.