Application of pareto genetic algorithm optimization to the design of broadband dipole elements for use in the Long Wavelength Array (LWA)

The application of Pareto GA multi-objective optimization to the design of planar dipole antennas for use in the LWA has been presented. The Pareto GA was used to optimize antenna performance in terms of sky noise frequency response and radiation pattern quality over the 20 MHz to 80 MHz band assuming the antenna is operated directly over an average lossy earth. It was shown that it is possible to design an antenna with radiation patterns that conform well to a sin(thetas) profile over the entire operating band with minimal pattern ripple at higher frequencies. However, high sky noise dominance cannot be achieved over the entire band with such a design. Antenna designs exist, which exhibit 6 dB dominance over the entire band, though this comes at the expense of reduced pattern beamwidth and higher pattern ripple. For the antenna geometry considered, improved design trade-offs can only be achieved by placing a metal reflector beneath the antenna; this is a topic for further investigation using Pareto GA optimization.