In this article, the radiation properties of a slot-loaded cylindrical dielectric resonator antenna (CDRA) have been analyzed strategically to realize a dual-band operation with a higher gain. A microstrip line based aperture coupled feed is adopted to excite dual modes at 4.8 GHz and 8.28 GHz with an impedance bandwidth of 5.84% (280 MHz) and 10.62% (880 MHz), respectively. A superstrate layer is placed at a suitable gap above the antenna structure to enhance the antenna gain by utilizing the principle of multiple reflections. For the further improvement of gain, a plus-shaped slot is incorporated on the superstrate that helps to concentrate the radiated field at the center of the superstrate, thereby the directivity of the CDRA has been enhanced on a large scale. The proposed structure is fabricated and measured for experimental verification that demonstrate 3 dB augmentations in antenna peak gain in comparison to the conventional CDRA. The experimental result shows a good agreement with the simulated ones. Higher measured peak gains of 7.87 dBi and 7.91 dBi at two operating bands ensure the applicability of the proposed simple structure for high gain wireless applications.