Amplitude and phase control in SIW structures by tuning multilayered graphene

Graphene is a unique 2D material that provides exceptional mechanical properties, ultra-high carrier mobility, and dynamically adjustable surface conductivity, making it an excellent choice for microwave devices. However, the dynamic manipulation of amplitude and phase in substrate integrated waveguides based on multilayered graphene has not been experimentally proven. In this paper, we propose a novel multilayered graphene based half mode SIW attenuator and phase shifter for the manipulation of amplitude and phase at microwave frequencies. The amplitude and phase are controlled by applying a bias voltage to graphene. The applied voltage is increased from 0 to 6.2 V, and the sheet resistance (Ω/□) of graphene can be tuned between 1302 and 60 Ω/□, depending on the gap size for deposition of graphene. The simulated and measured results of the proposed attenuator and phase shifter demonstrate the manipulation of microwave signals. The dynamic range achieved for amplitude is 13dB, and that of phase is 45 degrees. The proposed technique proves that the amplitude and phase of microwave signals can be tuned in SIW based devices without any localized surface mounted devices (SMD) or complex realization techniques.