A comparative study using numerical models on the mutual coupling (MC) between two different heterogeneous beam steering dielectric resonator antennas (DRAs) and an omni-directional dielectric resonator antenna (DRA) is presented in this paper. The mutual coupling was investigated by varying the separation between the antennas and manipulating the far field radiation pattern of each antenna. Several arrangements with element separation ranging from 0.1 to 0.5 free space wave length were investigated at the design frequency of 10 GHz. Different configurations contributed to different isolation levels. It was found that a significant isolation (< -15 dB) between an array of heterogeneous DRAs can be obtained even with antennas placed in close proximity (0.1 free space wavelength separation). It was also shown that the resonant frequency and return loss are most affected at settings where the direction of the main lobe of antenna A overlaps with the direction of the main lobe of antenna B. The expected inverse proportionality between 'd' (the separation between two antennas) and the level of MC was also demonstrated.