A new modified microstrip-line-fed rectangular dielectric resonator antenna coupled with slotted ground plane for circular polarization, is proposed in this article. The circular polarization is achieved due to combination of modified microstrip-line-fed aperture slot on ground plane. The proposed antenna offers 3-dB axial ratio bandwidth of 16.52% (at center frequency 3.57 GHz) in the broadside direction and -10 dB impedance bandwidth of 17.87% (at center frequency 3.58 GHz). The average gain and radiation efficiency is 4.69 dB and 74.84% in the working band. It is observed that the proposed antenna is right hand circularly polarized in broadside direction. The proposed antenna is suitable for Wi-MAX applications. © 2016 Wiley Periodicals, Inc.