The FDTD algorithm have been widely used in solving electromagnetic problems. However, stair-case representation of Yee grid may cause an undesired error in treating curved surfaced objects. To weaken the effects of errors, various techniques have been studied by many researchers. One of the technique is static field incorporation algorithm which can be applied to the edge of conductive objects. In this thesis, this algorithm is expanded to the bow-tie antenna which has inclined edge boundaries. The proposed algorithm shows a good result compared with the MoM result which is accurate for bow-tie structures. Finally, the stability analysis of the algorithm is mentioned and proposed new stability criterion for this algorithm in the last section.