Modelling of a linear Wideband Array Antenna for Pattern Optimization and Synthesis using differential evolution

Abstract

newline Abstract newlineApplication of mathematical and geometrical concepts such as fractals newlinecan provide elegant solutions to complex antenna array design. For newlineexample, design issues such as beam shaping and control, side lobe newlinelevels, bandwidth and many others have been addressed by erstwhile newlineresearchers. In particular, the multi-scaling makes them attractive for newlinewideband / UWB applications. This led to the application of fractal newlinegeometry principles which offer optimized solutions for the design of newlinemultiband antennas and arrays. Designs based on fractal concepts have newlineproduced multi-band arrays as well as array configurations that are fairly newlineinsensitive to bandwidth, but with limited side lobe level suppression. newlineTo overcome these difficulties polyfractal arrays, constructed from newlinemultiple generators associated with connection sequence, are considered newlinein this dissertation. In turn, the deterministic fractal arrays are newlineessentially polyfractal arrays that have single generator to scale all newlineiterations. newlinePrimary parameters like Directivity, Main Lobe Beamwidth, and First newlineNull at the required direction for antenna characterization, Peak Side lobe newlineLevel Control, Mutual Impedance and the Driving Point Impedance for newlineArray performance are considered in this thesis. newlineCantor set based fractal analysis is presented for the parameters of newlinearray with optimum selection of Scaling factors and number of iterations newline(stages) that gives the best performance of the considered parameters. newlinei newline newlineAndhra University, Visakhapatnam newlineAndhra University, Visakhapatnam newlineHowever the design of the final array configuration does not give newlineperformance for multi parameter optimization simultaneously. newlineIn order to improve this situation, polyfractal approach provides array newlinewith considerable performance improvement and different sets of newlinegenerator configurations are considered to arrive at the best performance. newlineVariants of Fractals viz., polyfractal arrays are considered for optimization newlineof element locations with basic performance pa