A singly-fed wideband circularly polarized dielectric resonator antenna (CPDRA) is proposed in this paper. Antenna structure contains a rectangular and two half split cylindrical dielectric resonators (DRs). Multiple orthogonal modes are excited in the antenna structure when excitation is applied through a stair-shaped slot. Measured results show that antenna provides wider 3-dB axial ratio (AR) and impedance bandwidths of 41.01% and 49.67%, respectively. Proposed antenna can be utilized in C-band applications.

A two port multi-input-multi-output (MIMO) dielectric resonator (DR) antenna (DRA) is proposed with circularly polarized radiation. The antenna geometry allows to find circular polarization and improved impedance bandwidth by reducing the separation between the DR elements. The isolation between the ports of the antenna remains more than 15 dB in the operating passband even after reducing the separation between the radiating elements. The antenna provides the 10-dB impedance and 3-dB axial ratio bandwidth of 34.85% and 4.55%, respectively. The MIMO performance of the proposed antenna is confirmed by calculating the parameters like envelop correlation coefficient, diversity gain, mean effective gain, channel capacity loss, and the total active reflection coefficient. The proposed antenna can be utilized for C-band applications.

A technique is implemented for obtaining the circular polarization in a nano-dielectric resonator (DR) antenna. A cylindrical DR has been excited by a nanostrip feedline. The application of input Gaussian pulse at the corner of feedline splits the field components into two parts. These field components travel at the edges of the feedline with a quarter wavelength path difference between them. The coupling of these field components to DR provides the circularly polarized response. The antenna is designed for operating in the optical C-band. The proposed antenna provides the 10 dB impedance bandwidth of 11.58% (187–210 THz) and 3 dB axial ratio bandwidth of 5.72% (188.5–199.6 THz).

A multiband dielectric resonator (DR) antenna is proposed with dual band circularly polarized (CP) response. This antenna consists of an inverted-sigmoid shaped DR. A metallic strip is applied at the surface of the DR to achieve the circular polarization. The fundamental and higher order hybrid modes are excited in the antenna structure because of the specific geometry. The antenna with dual band CP response provides the measured 3-dB axial ratio (AR) bandwidth of 19.98% in the lower band and 3.07% in the upper band. The upper band 3-dB AR response can be tuned in different 10-dB impedance passbands of the antenna by changing the location and width of the metallic strip. Antenna response can also be tuned to obtain the triple band CP operation.