Investigation on Mutual Coupling of Aperture Coupled Cylindrical Dielectric Resonator Antenna (DRA)

Abstract

In this research, study on mutual coupling of aperture coupled cylindrical DRA and its influence on return loss, radiation pattern including the directivity, gain and bandwidth was computed and illustrated. The DRA was excited by a micro strip line with aperture coupled slots where the slot locations were calculated using the characteristic of standing wave ratio over a short ended micro strips. Small dielectric resonator antenna was designed using high permittivity dielectric material with permittivity the substrate of 3.38. The diameter of the dielectric resonator is 12mm with the height of 4.2mm. The element spacing that been investigated for the effect of mutual coupling was at 0.5λ, 0.75λ and 1λ with maximum of four DRA been used. The final result shows the effect of mutual coupling is decreased with three DRA element with the gain measured at 5.948GHz frequency is about 8.619dB with high directivity measured at 11.4dBi. This shows that the proposed DRA with three 1λ spacing DRA elements exhibits an enhancement of the gain and directivity in comparison with a single pellet DRA. Hence, by increasing the level of isolation between the two identical DRAs to 1λ it actually helps electromagnetic interaction to attract and further increase the directivity and effective area.