Evaluation of antenna radiation Q using FDTD method

Introduction: Miniaturisation of RF devices is very important for development in the next generation of wireless communication systems. The size reduction technique must be applied not only to the RF circuit but also to the antenna. The size of antenna is the most difficult parameter to reduce. The quality of antennas can be evaluated using the quality factor Q. This quantity of practical interest is very important to characterise electrically small antenna performances (the higher the antenna Q the smaller the impedance bandwidth). For an antenna, the following definition for radiation Q is generally accepted: