Joshi, A., and R. Singhal. “Coaxially Fed Hexagonal Patch Antenna for C- and X-Band Applications With Reduced-Ground Plane”. ECTI Transactions on Electrical Engineering, Electronics, and Communications, Vol. 17, no. 2, Aug. 2019, pp. 136-43, doi:10.37936/ecti-eec.2019172.219184.