A novel wideband rectangular dielectric resonator antenna (RDRA) is proposed in this paper. An equivalent air-dielectric DRs blocs are introduced inside the resonator to enhance the structure’s bandwidth. The hybrid structure is excited by a simple Microstrip feed line, adapted with a stub at the end of the line. The resonant modes of the isolated DR and the air-dielectric DRs, are merged together to form a wideband impedance bandwidth. Through this paper, it is demonstrated that the bandwidth of a simple rectangular DR antenna can be greatly enhanced by air-dielectric DRs. A detailed parametric study is carried out to analyze the characteristics of the proposed antenna. Simulation results show that the proposed RDRA has a 10 dB impedance bandwidth of 365 MHz, from 1.78GHz to 2.15GHz and the radiation pattern is quasi-stable over the operating range of frequencies.