Investigation of SRR slot on monopole antenna

The antenna performance in achieving better return loss, gain, and efficiency can be potentially worked out by adding Split Ring Resonator (SRR) slot to the antenna structure. Thus, this paper investigates the effect of SRR slot on a monopole antenna at wideband frequency ranged from 2.9GHz to 6.6GHz. All antenna designs involved in this paper is simulated using Computer Simulation Technology (CST) software in open space environment. The designed process are done by using FR4 epoxy board as the substrate with dielectric constant of 4.4 and tangent loss of 0.019. The antenna performance is studied based on the antenna parameters such as frequency, return loss, gain, directivity, and efficiency. The results shows that the horizontal shifting of SRR slot has improved the return loss of the antenna by 4.4dB with the maximum frequency shifting of 120MHz. Significantly, the vertical shifting of SRR slot has improved the return loss, gain, and efficiency of the antenna by 6.9dB, 1.9dB, and 2.9dB respectively at 3.6GHz. At the same time, the directivity of antenna is maintained with at least 2dBi. However, the increment of the number of SRR slot will increase the return loss by 5.9dB and reduce the gain and efficiency by at most 3.4dB and 3.8dB respectively.