Effect of slit orientation of the metamaterial split ring resonators on the performance of the microwave filter in the X-band frequency range

Abstract

Double Hexagonal Split Ring Resonators (SRR) has been investigated to determine the effect of ring gap position on bandwidth, insertion loss, and resonance frequency in the X-Band frequency range (8 - 12 GHz). The position of the inner and outer ring gap was varied either on the side or the corner of the SRR. The effects of ring gap position were numerically using the finite element method. A Similar frequency response was observed when the gaps of inner and outer SRR are oriented 180° each other. The variation of the gaps in the inner and outer ring angles of the SRR results in a frequency response at a ring gap angle of 0° equal to 180°, an angle of 60° to 300° and an angle of 120° to 240°. In the variation of the inner and outer ring gap on the side of the ring, the frequency response at the ring gap angle of 30° is equal to 330°, the angle of 90° is equal to 270° and the angle of 150° is equal to 210°. The bandwidth, insertion loss and resonant frequency show sinusoidal variation with SRR gap orientation angle. If the ring gap were to be deployed at the corner, it was obtained a great frequency response, the wider bandwidth and the smaller insertion loss than the variety of ring gap at the side. To get the filter with a good frequency response, the wider bandwidth and smaller insertion loss, hence the filters were made with the inner and outer ring gap positions located at the corner. The optimal geometry where the resulting good frequency response, small insertion loss, and wide bandwidth is the structure with the inner ring gap position at an angle of 180° and the position of the outer ring gap at an angle of 0°.