Ultra wideband butler matrix for beam-forming network

Abstract

The need of having passive microwave devices that can operate in Ultra Wideband (UWB) frequency range has been arising these days due to their features that capable in bringing significant advances in wireless communications such as low power consumption, minimal interference and large channel capacity. However, the low power consumption has led to short range communication. Butler Matrix Beam Forming System is one of the solutions to solve such issue. Multilayer UWB couplers and multilayer UWB phase shifter are possible devices to develop a compact system design of Butler Matrix for UWB as the crossover function has been eliminated by this technique. New designs of multilayer UWB couplers and multilayer UWB phase shifters, which are used to construct the UWB Butler Matrix are introduced. These two main components are designed to function in the UWB frequency range to permit construction of the UWB Butler Matrix. In this research, the proposed UWB Butler Matrix achieves an improvement of 18.6% wider bandwidth compared to available UWB Butler Matrix and 31.1% size reduction compared to planar configurations of Butler Matrix. Simulation results are obtained by using Computer Simulation Technology Microwave Studio 2012. All measurements of S-parameters and phase differences performances are performed using a Vector Network Analyzer. Meanwhile, the measurements on beam directions of the UWB Butler Matrix are steered towards a particular direction by switching the input port accordingly. The switched beam antenna array system shows that four orthogonal beams are produced at four different directions. All measurements result show a very good agreement with the simulation results