Here some papers related to “feasible” circular CP patch antenna design.
“Open question”: where we can get the material related to actual antenna design? We could consider it as basic benchmark for working on improvements with the new design.
A_Compact_Circularly_Polarized_Antenna_for_5.8-GHz_Intelligent_Transportation_System.pdf
An_Electromagnetically_Coupled_Circularly_Polarized_Antenna_for_ISM_Application_at_2.45_GHz.pdf
EbNo
**http://kon**fluence.org/media/fun/It'sAllAboutEbno.pdf
Full Link Budget review
https://itso.int/wp-content/uploads/2018/04/Link-Budget-Analysis-1.pdf