Numerical model for phase distribution characterization of reflectarray elements

A mathematical model to obtain a linear progressive phase distribution of six different high performance reflectarray resonant elements in order to realize a planar wave in front of the periodic aperture is formulated in this paper. All the resonant elements under characterization are tuned to operate at X-band frequency range using commercially available CST computer model. The reflection phase curves for each resonant element are then calculated by using analytical equations based on a periodic Method of Moments (MoM). A Figure of Merit (FoM) has been defined for the comparison of reflection phase curves obtained by both simulation and formulation in terms of bandwidth and static phase range performance. It has been demonstrated that among the entire resonant elements triangular loop acquire steepest phase characteristics gradient offering higher static phase range of 190° with minimum bandwidth, whereas rectangular patch element is shown to exhibit smoother phase characteristics gradient giving lower static phase range of 120° with broader bandwidth performance. Furthermore it has been observed that triangular loop depicts the maximum reflection loss of 3.90dB, whereas rectangular patch shows the minimum reflection loss of 0.23dB.