Planar implementation of butler matrix feed network for a switched multibeam antenna: A survey

In recent years, high-speed wireless communication is in vogue. In wireless communication systems, multipath fading, delay and interference occurred by reflection or diffraction. In a high-speed wireless communication, it becomes a necessary to separate desired signal from delay or interference signal. Thus to overcome these problems Smart antenna systems have been developed. Basically there are two types of smart antenna systems; one is Switched beam system and another Adaptive array system. This paper presents Survey of the optimum design of a 4×4 planar Butler matrix array as a key component of a switched beam smart antenna system with the components (micro strip antenna, hybrid couplers, cross-coupler, phase shifter) used to implement the matrix.