Realizing a directive antenna using low profile devices has attracted many researchers’ attention in antenna engineering. Nowadays, in many applications like automotive radars and satellite communications, efforts are concentrated on building simple and low profile antenna for generating very narrow beams. Increasing the size of the radiating aperture only results in increasing directivity when aperture is illuminated optimally. But until now, uniform aperture illumination has been achieved by reflector and lens antennas but large distance between feed and aperture causes these kinds of antennas to be so large. By employing array antennas, desired aperture efficiency can be achieved but designing their feed networks is followed by increasing cost and complexity. Metasurfaces are 2D structures with subwavelength thickness that make it possible to define new applications of electromagnetic waves in low profile and simple designed devices. Utilizing passive metasurface within the antenna aperture and its proper excitation can substitute the last samples of array antennas. The goal of this thesis is to design and simulate a dihedral corner reflector antenna that can be used for directive applications by employing bianisotropic metasurface. A semianalytical method for more rigorous prediction of mentioned antenna radiation characteristics is declared and then, antenna performance is evaluated by both full-wave and semianalytical methods. For instance, the optimal directivity 17.59dB and side lobe level -12.62dB are derived for broadside radiation by full-wave simulations at frequency of 20GHz which are in good agreement with semianalytical method results. Then, rendered antenna is modified for profile reduction and repeatedly designed by using semianalytical method for accomplishing desired radiation characteristics. Key Words : Metasurface, Antenna, Electromagnetic Devices, Highly Directive, Aperture Efficiency.