A Pattern Reconfigurable MetamaterialBased Antenna for Sub-6G MillimeterWave Application

Abstract

The increasing number of applications, services, and use case scenarios triggers the evolution from the fifth generation (5G) towards the sixth generation (6G). 6G has been envisioned to utilize the sub-THz (90-300 GHz) (upper mmWave) and THz (0.1-10 THz) bands. At such high frequencies, high path loss and atmospheric absorption are critical challenges. A highly directional and reconfigurable antenna is required to mitigate these challenges. In this paper, a novel pattern reconfigurable metamaterial-based antenna for sub-mmWave applications is proposed. The antenna is based on a graphene metasurface loaded with a novel square-spherical split ring (SSSR) resonator, placed above a rectangular microstrip patch antenna to provide absorption of unwanted signal and improve gain and spectral efficiency. Placed under the patch is Rogers 5800 substrate with permittivity (ε) of 2.0 and thickness of 0.1mm. The antenna operates between 90-120 GHz spanning the 102-109 GHz adopted at the WRC 2023 for advanced use cases of 6G and was simulated using CST suite. The main beam is pattern reconfigured by two PIN diodes (d1, d2) embedded on the patch antenna. d1 switches between 90-98 GHz, obtaining a maximum radiation pattern of -70.7 dB at 97.5GHz, while d2 switches between 98 -120GHz, realizing a -69.6dB peak radiation pattern at 105.4GHz. When fully loaded, a -64.5dB was obtained, better than similar work compared. The antenna is compact, has a wide bandwidth, and can perform efficiently in 6G use cases such as holographic presence, and smart transport among others requiring high radiation efficiency.