Design and Implementation of Butler Matrix

Abstract

This paper describes the design and implementation of 4x4 Butler matrix. The design specification is at 3.5 GHz. Small and easy to fabricate microstrip layout topology for the 4x4 Butler matrix have been designed and constructed relying on a low cost dielectric material, the well-known FR4. The compactness of the system is depending on the design of Branch-line Coupler. Design of Branch-line coupler is discussed and simulation results are also presented. The simulation and fabrication results will be compared and discussed. Index Terms-Butler matrix, Branch-line coupler.