Design of dual-band dual-polarized wire antennas using a genetic algorithm

A new dual-band polarization-agile wire antenna element is presented along with a method of tuning the resonant frequency, impedance, and radiation pattern of the antenna. The four terminal antenna can radiate in one of two modes: dipole mode or slot mode. Ideally, the radiation patterns and resonant frequencies of the two modes are identical and their polarizations are orthogonal in every direction. Superposition of the two modes will allow for the synthesis of any linear, circular, or elliptical polarization, and identical mode radiation patterns and orthogonal mode polarizations will allow for synthesis of any polarization in any direction. This polarization synthesis capability makes the polarization-agile wire antenna element a natural for inclusion in smart antenna systems. The resonant frequencies, impedance, and radiation patterns of the antenna are tuned through additional wires that may be thought of as integrated tuning stubs. These tuning stubs will allow the polarization-agile wire antenna to radiate each mode effectively at multiple specified frequencies. Genetic algorithm optimization techniques have been used in the development of the polarization-agile multiple-resonant wire antenna with impedance-matched resonant frequencies of 30 and 45 MHz for both the slot and dipole modes.