Arm Angle Dependence of X-shaped Metamaterial Resonator in the X-band Regime

An angle dependent tunable design of an X-shaped metamaterial resonator (MMR) was theoretically and experimentally investigated in X-band (8–12 GHz). Single X-shaped MMR structures made of copper were simulated by changing the angle θ (w.r.t. magnetic field axis), and the data was confirmed experimentally with a Vector Network Analyser (VNA). The results indicated that with increasing angle, the resonance frequency was shifted towards the higher frequencies. Surface current data attributes the resonance to its magnetic component. Furthermore, the effective intrinsic parameters were calculated using Nicolson-Ross-Weir (NRW) technique to verify the metamaterial behavior of the resonator. The model with θ = 60° showed the best response, with a low return loss and a high figure of merit (FOM), which can be used for X-band stealth applications and radar communications.