A novel approach to evaluating the gain-bandwidth potential of antennas

This paper presents a novel approach to evaluating the gain-bandwidth potential of antennas. The measured or calculated antenna impedances are approximated by positive real rational functions using a powerful numerical method, called the real frequency technique. A proper topology and lumped element values of the antenna realized by the rational function is treated analytically by making use of the well-known Fano´s (1950) theory to determine the gain-bandwidth relationship. Neither an a priori choice of the model topology nor an analytic form of the rational function is required. An example is given to show the applications of the method.