This paper is concerned with a numerical study of a novel edge termination technique for 4H-SiC high voltage devices. For the first time, Buried Field Rings (BFRs) are proposed to be used in SiC devices as an effective termination method and the concept is numerically demonstrated for 4H-SiC MESA JFET structures. By using 4 BFRs at the periphery of a MESA JFET, a breakdown voltage of 1590V has been achieved, representing more than 90% of the ideal bulk breakdown value (1750V). The doping concentration sensitivity of the rings and the effect of the SiC/SiO2 interface charge on the blocking capability are studied, evidencing the robustness of the novel concept in terms of process conditions and doping variations. For comparison, some results for GRs and JTE are also presented.