###### Abstract
Single feeding approach includes slot coupled feeding, m-line feed and coaxial probe feed. Dual/Complex feeding is effective to achieve wide AR bandwidth. The drawback is circuit complexity, increased loss, high cost and making the design bulkier [29]. Thus, to design compact, cost effective and wide AR bandwidth CP DRAs, researchers prefer to adopt the simple feeding mechanism. Researchers have devised multiple techniques to obtain circular polarization. These include stair shaped DR, stacked DR, spidron fractal geometry DR and many more. A circularly polarized quarter wave fed DRA prototype for C and X-band UWB applications with overall size of 25 \(\times\) 25 \(\times\) 8 mm\({}^{3}\) is proposed in [29]. The design has a maximum gain of 6 dBic, 63.8% of Impedance Bandwidth (IBW) and 63.8% of AR bandwidth. It comprises of two rectangular shaped DRs and F-shaped defected ground structure. An extra-large size of 90 \(\times\) 90 \(\times\) 15 mm\({}^{3}\) slot coupled circularly polarized DRA with two annular vias in the radiator, having \(-10\) dB operational bandwidth of 7.29% and 3 dB AR bandwidth of 5.5% with peak gain of 6-7.1 dBic, is reported in [30]. In [31], an AMC (Artificial Magnetic Conductor) based miniaturized DRA is proposed. The design operates at 3.5 GHz of 5G band with 14.2% impedance bandwidth. The design has over all dimensions of 50 \(\times\) 50 \(\times\) 6.6 mm\({}^{3}\). The gain and efficiency of the design are 6.87 dBicand 74% respectively. Although the design is compact and has good overall performance, but the drawback is that it is not circularly polarized. For C band satellite communication application, lower Ku band and overall UW dual band CP characteristics are achieved with the help of I-shaped monopole and two rectangular shaped orthogonally placed dielectric radiators, which is presented in [32]. The proposed design has a large size of 63 \(\times\) 75 \(\times\) 6.08 mm\({}^{3}\). Moreover, peak gain of 7 dBic with IBW of 146.33% and AR BW for first and second band are 17.28% and 11.56%, respectively. In [33], five layers CP DRA with stacked rectangular radiators fed by substrate integrated waveguide is discussed. The design has dimensions of 23 \(\times\) 23 \(\times\) 2 mm\({}^{3}\) with AR BW of 27%, IBW of 30% and peak gain of 6.5 dBic for Ku-band satellite communication. A long heightened dual mode CP RDRA of the size 40 \(\times\) 40 \(\times\) 18 mm\({}^{3}\), fed with stair-shaped microstrip line, operating in the range of 2.9 to 3.9 GHz for Worldwide Interoperability for Microwave Access (Wi-MAX) applications is discussed in [34]. The design has an AR BW of 17.5% and peak gain of 4.2 dBic. In [35] a CP Cylindrical Dielectric Resonator Antenna (CDRA) with a microstrip line edge feeding and a J-shaped modified defected ground for WI-MAX and LTE applications is discussed in detail. The proposed design has a size of 40 \(\times\) 32 \(\times\) 14 mm\({}^{3}\). The design has IBW of 41.44%, an AR BW of 29.91% and maximum gain of 2.84 dBic. In [36] an extra large sized low gain CP RDRA with improved AR BW of 55.22% and IBW of 66.45%, possessing peak gain of 6.5 dBic and large size of 80 \(\times\) 80 \(\times\) 5 mm\({}^{3}\), is presented. The design is excited with a microstrip line, coupled with stair-shaped slotted defected ground and edged-cut dielectric resonator with conductive coating. In [37] a slot coupled square shaped CP Dielectric Resonator Antenna (CP SDRA) for WLAN applications with off centered microstrip line feeding is discussed. The design has overall dimensions of 44 \(\times\) 45 \(\times\) 11 mm\({}^{3}\), with \(-\)10 dB return loss of 9.25% and an AR BW of 7.94%, respectively. In [38], a long heightened passive metal strip loaded and coaxial fed C-shaped CP RDRA for WI-MAX is presented. The design has a size of 45 \(\times\) 40 \(\times\) 15 mm\({}^{3}\). The design has gain of 5.2 dBic with IBW and an AR BW of 24.72% and 12.28%, respectively. Whereas in [39], an inverted sigmoid shaped CP dual band DRA with passive loaded metallic strip is discussed.