In theory, tapered slot antennas generally have wide bandwidth, high directivity and are able to produce symmetrical radiation pattern. It also simple feed structure, and easy for fabrication. This type of antenna has been applied to satellite communications, remote sensing, and radio telescope. The advantages of endfire tapered slot antennas include producing a symmetrical beam in the E-and H-plane or changing beamwitdh by varying the shape, length, dielectric thickness and dielectric constant of the tapered slot antenna