▎ 摘　　要

Electronic whispering gallery modes (EWGMs) have been recently observed in several circular graphene junctions, pn and pp ', created in scanning tunneling microscopy experiments. By computing the local density of states within the Dirac-Weyl formalism for massless fermions we demonstrate that the EWGMs may really be emerged in any type of the electrostatic-potential induced circular graphene junctions, including uni-junctions (e.g. np- or pp '-junctions) as well as bipolar-junctions (e.g. pnp-heterojunctions). Surprisingly, quantitative analyses show that for all the EWGMs identified (regardless of junction types) the quality (Q) factors seem to be