In this article, a wideband circularly polarized half-split cylindrical dielectric resonator antenna (HS-CDRA) having two layers with different permittivity in radial direction is investigated. Designed antenna is excited by a new modified CPW fed which consists of signal line, helps to realization of circular polarization, half-split cylindrical dielectric resonator (HS-CDR), to confirm that circular polarization in proposed antenna. HS-CDR is made of two different materials which can supports to enhance the input impedance bandwidth and 3-dB axial ratio bandwidth. From the distributions of E-fields in HS-CDRA, it is observed that TM11 δ mode has been excited. To confirmed the circular polarization in proposed antenna, E-field distribution on different phases (φ = 0º, 90º, 180º, and 270º) have been plotted. This antenna provides measured −10 dB input impedance bandwidth of 25.94% (centered on 4.70 GHz) and 3-dB axial ratio bandwidth in broadside direction of 17.34% (centered on 4.90 GHz). The average gain and radiation efficiency in working band are 1.56 dBi and 93.43% in broadside direction, respectively. CP radiation pattern shows that the proposed antenna has left hand circular polarization and this developed antenna could be useful for wireless applications like WLAN/Wi-MAX bands. © 2016 Wiley Periodicals, Inc.