Hi Sir,
I had a research experience of 3+ years in antenna designing using CST Microwave Studio and Ansys HFSS. I has gone through your requirements, where the Circularly Polarized Dielectric Resonator Antenna (CP-DRA) should be designed at sub-6GHz band for 5G communication.
I will explain you how the DRA is working and I will explain the MODES of the dielectric resonator antenna. At which mode the DRA is radiating, Axial ratio plot for Circular Polarization will also be explained. I will provide a video for you, which will have design of DRA in CST and it will be for your future reference. I will even provide some reference IEEE papers and some DRA books.
If you feel interested, please have a discussion in freelancer chat box. I am ready to discuss with you.
Thanks