Exploring the Optimal Solution for Graphene-Based Microstrip Line Attenuators

This study explores optimization strategies for the attenuation performance and modulation depth of Graphene-based Microstrip Line Attenuators (GMSLAs). Existing GMSLAs mainly rely on rectangular attenuation units, such as single-layer graphene sheets and graphene composite sandwich structures, which have limitations in meeting diverse performance requirements. To address this, this study systematically investigates which configuration within the same class of structures yields the most optimal and reliable attenuation performance. Using finite element simulations, this study systematically examines the attenuation performance and modulation characteristics of graphene ring-shaped attenuation units with five distinct geometric configurations (circle, regular triangle, square, regular pentagon, and regular hexagon) in the 40-70 GHz V-band. The results indicate that among individual units, the hexagonal unit exhibits the highest average reflection transmission loss and modulation depth. The triangular unit demonstrates a relatively stable and high average reflection transmission loss as well as the most stable modulation depth, whereas the square unit possesses the most stable average reflection transmission loss. Furthermore, by adjusting the rotation angle of the hexagonal units, significant polarization-dependent attenuation was observed. When combining multiple hexagonal units, their performance exceeded the simple sum of individual unit performances, showing superlinear growth. This study overcomes the limitations of traditional graphene attenuation unit designs by introducing a range of geometric configurations, offering new insights into the development of highly efficient, tunable attenuators with superior performance in high-frequency bands.