Abstract
A series of parameterization analysis consists of the substrate thickness and permittivity is carried out to enhance the bandwidth performance of reflectarray antenna element. The parameter to measure the bandwidth performance is including the phase curve slope and linear phase range according to reflection phase to the frequency graph. Return loss is also analysed to determine loss performance occurred by substrate material. The concentric split ring square element is designed and analysed using computer software tool csT Microstripes. The analysis shows that both substrate thickness and permittivity affects the bandwidth performance of element where the suitable selection of substrate material should be done to achieve the optimum performance of element especially the phase slope and phase range.