  In recent years, high-speed wireless communication is in vogue. In wireless
communication systems, multipath fading, delay and interference occurres 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 the optimum design of a 4x4
plannar Butler matrix array as a key component of a switched beam smart antenna
system, operating at 5.2 GHz for WLAN with a dielectric substrate, FR4 of er
=4.9 and h=1.6mm. Conception details, simulation results and measurements are
also given for the components (microstrip antenna, hybrid couplers,
cross-coupler, phase shifter) used to implement the matrix. In this
dissertation, mathematical calculations for all the components using MATLAB is
done and then every individual component is designed using the commercial
software SONNET. Then these entire components have been combined on a single
substrate and simulated using SONNET.
