Modern Antenna Design Using Mode Analysis Techniques

In this paper, the modal theory of antennas is re-visited, believing that it brings invaluable information towards facilitating the design of multi-feed multi-band antennas. First, some subtle changes are proposed to enhance the applicability of the theory. Next, using some efficient computational techniques, the proposed formulations are shown to predict, to a very high accuracy, the input impedance of any antenna under study. This greatly simplifies the antenna problem and focuses design efforts on finding the appropriate complex resonance frequency to cover a required band. Finding the appropriate feed location is then a matter of extracting the corresponding impedance map for this antenna through simple field manipulations.