Dual mode modified double square ring resonator structure at 76 GHz

Abstract

Dual mode modified double square ring resonator (MDSRR) operating at 76 GHz millimeter-wave has been simulated, and experimentally verified. MDSRR structure operates in two modes, metamaterial (MTM) mode and frequency selective surface (FSS) mode, depending on the direction of the electric field. The MDSRR in the MTM mode performs well at the desired frequency region by providing the highest insertion loss, S21, as reported in the literature with a loss of −0.5 dB. The electromagnetically induced transparency principle is applied to explain the loss reduction mechanism. The low losses MTM structure has the potential to enhance the performance of the radiating elements of the automotive radar systems. Conversely, in the FSS mode, the FSS characteristics of the proposed structure are numerically simulated and verified experimentally by changing the direction of the electric field along the x-direction, in which the structure shows opposite behavior compared to the MTM performance. To demonstrate the validity of the FSS characteristics, the MDSRRs structure was tested using a waveguide measurement facility. The experiment results match well with that of the simulation, and wideband-stop characteristics are introduced in the range of 74 GHz to 80.3 GHz.