Analysis and design of a planar two-dimensional retrodirective array reflector

Previously the authors have used planar antennas and printed transmission lines to implement the array reflectors. Due to the simplicity and conformability of the structure, these planar retrodirective reflectors may be suitable for use in the vehicle collision avoidance systems to enhance the radar echoes from vehicles or roadside obstacles. In this paper, a 3/spl times/4 planar Van Atta array reflector is analyzed and realized. Unlike those in the previous investigations, this reflector possesses a two-dimensional retrodirectivity, which means that it can produce broad reflected-field beamwidth both in E-plane and H-plane of the antenna array. To understand the scattering characteristics of the retrodirective reflector, the method of moments (MoM) and the physical optics (PO) together with the method of equivalent currents (MEC) are used to analyze and design the reflector. Numerical and measured results are presented, which show good agreement with each other.