A wide band circularly polarized planar antenna of high radiation efficiency is proposed in the present work for future generations of wireless communications requiring circular polarization in the X-band of the microwave spectrum. The main radiating part of the antenna is a rectangular turn-shaped strip that is capacitively loaded by two corner-shaped parasitic elements. The antenna is fed through coplanar waveguide (CPW) region whose ground structure is defected by etching two rectangular annular slots. The purposes of both the corner-shaped parasitic elements and the rectangular annular slots of the CPW ground plane are to increase the impedance matching and the 3 dB axial ratio (AR) bandwidth, and to enhance the antenna efficiency. The design is achieved through complete parametric study to find the optimum dimensions of the antenna. A prototype of the proposed antenna is fabricated for experimental assessment of its performance. The results obtained by both simulation and experimental measurements show that the impedance matching bandwidth is about 5.3 GHz (8-13.3 GHz); the 3 dB AR bandwidth is about 3.1 GHz (8-11.1 GHz); the maximum gain ranges from 4.5 to 5.5 dBi; and the radiation efficiency is higher than 98% over the operational frequency band.
2. Mondal, K., "Axial Ratio (AR) and Impedance Bandwidth (IBW) enhancement of Circular Polarized (CP) monopole antenna," AEU --- International Journal of Electronics and Communications, Vol. 134, 153649, 2021.
3. Chen, B. and F. S. Zhang, "Dual-band CPW-fed circularly polarized slot antenna with improved ground plane structure," Progress In Electromagnetics Research Letters, Vol. 46, 31-36, 2014.
4. Jaiverdhan, M. M. S., R. P. Yadav, and R. Dhara, "Characteristic mode analysis and design of broadband circularly polarized CPW-fed compact printed square slot antenna," Progress In Electromagnetics Research M, Vol. 94, 105-118, 2020.
5. Radhakrishnan, R. and S. Gupta, "Axial ratio tuned circularly polarized slot-loaded antenna for S-band and C-band applications," Progress In Electromagnetics Research C, Vol. 113, 239-249, 2021.
6. Bao, X. L. and M. J. Ammann, "Dual-frequency dual-sense circularly polarized slot antenna fed by microstrip line," IEEE Trans. Antennas Propag., Vol. 56, No. 3, 645-649, 2008.
7. Chen, C. and E. K. N. Yung, "Dual-band dual-sense circularly-polarized CPW-fed slot antenna with two spiral slots loaded," IEEE Trans. Antennas Propag., Vol. 57, No. 6, 1829-1833, 2009.
8. Chen, Y. Y., Y. C. Jiao, G. Zhao, F. Zhang, Z. L. Liao, and Y. Tian, "Dual-band dual-sense circularly polarized slot antenna with a C-shaped grounded strip," IEEE Antennas and Wireless Propagation Letters, Vol. 10, 915-918, 2011.
9. Saini, R. K., S. Dwari, and M. K. Mandal, "CPW-fed dual-band dual-sense circularly polarized monopole antenna," IEEE Antennas and Wireless Propagation Letters, Vol. 16, 2497, 2017.
10. Banerjee, U., A. Karmakar, A. Saha, and P. Chakraborty, "A CPW-fed compact monopole antenna with defected ground structure and modified parasitic hilbert strip having wideband circular polarization," Int. J. Electron. Commun., Vol. 110, 152831, 2019.
11. Ding, K., C. Gao, C. Y. Wu, D. Qu, and B. Zhang, "A broadband circularly polarized printed monopole antenna with parasitic strips," IEEE Antennas and Wireless Propagation Letters, Vol. 16, 2509, 2017.
12. Ding, K., Y. X. Guo, and C. Gao, "CPW-fed wideband circularly polarized printed monopole antenna with open loop and asymmetric ground plane," IEEE Antennas and Wireless Propagation Letters, Vol. 16, 833-836, 2017.