Tunability Performance of Reflectarrays Based on Non-Linear Material Properties

Limited phase range and narrower bandwidth are the main performance limitations of reflectarray antennas for high gain applications which result in the performance to be restricted particularly in satellite and earth observatory systems. This study provides a thorough investigation on the tunability performance of reflectarrays designed in X-band frequency range using different non-linear dielectric substrates. An investigation of phase agility characteristics of reflectarray rectangular patch antenna printed above non-linear materials (0.17≤ Δε ≤0.45) is thoroughly presented. A detailed analytical study on dynamic phase range and frequency tunability of the reflectarrays is carried out based on the analytical investigation which is validated by Finite Integral Method (FIM). As the dielectric anisotropy of non-linear materials increases from 0.17-0.45 the frequency tunability performance of the reflectarray antenna is shown to increase from 372-796 MHz. The results show that LC-B1 with a dielectric anisotropy of 0.45 contributes a maximum dynamic phase range and frequency tunability performance of 160° and 796 MHz respectively. The dielectric non-linear properties presented in this study are shown to considerably affect the frequency and phase range performance of reflectarray antenna particularly for rapid dynamic phase change of terrestrial systems.