First we define the various terms used to characterize antennas. Then a number of types of antennas that are commonly used in short-range radio systems are examined, including the dipole, monopole over a ground plane, loop, helical, patch, planar and inverted F, and we give examples of design. Metamaterials are described and we show how their special features have been applied to produce a wideband patch antenna. We review methods of matching the impedances of the antenna to the transmitter or receiver RF circuits, including mutual inductance matching to a loop antenna. An explanation of measuring techniques concludes the chapter.