Reflectivity of Reflectarrays Based on Dielectric Substrates

Problem statement: Reflectarrays provide a low cost and low profile solution for antennas required for high gain applications but their use is restricted in some applications due to the narrow bandwidth and high loss performance. These performance limitations can be attributed to different sources of reflectivity of the reflectarrays. This work provides a thorough investigation on the reflectivity performance of reflectarrays designed at 10 GHz using different dielectric substrates. Approach: The detailed analytical study of the characteristics and losses of the reflectarrays was presented and a number of dielectric substrates are used to design and analyze the reflectivity of the reflectarrays based on the analytical investigation which is validated by Finite Integral Method (FIM). Results: The results showed that the dielectric material with lowest dielectric permittivity and loss tangent values (Teflon) demonstrates an optimum reflectivity performance when employed for the reflectarray design. Conclusion: It was concluded from this research that material properties significantly affect the reflectivity of the reflectarrays and hence the bandwidth and loss performance can be pronounced improved by using a low dielectric substrate.