Butler Matrix Design for Smart Antenna in X-Band Applications

Abstract

In wireless communication, beamforming technique is used to cover the desired direction for the coverage of intended user in modern mobile needs. For this kind of application, an antenna was designed by using Rogers RT Duriod 5880 substrate to cover X-band frequencies [1]. 5G will be the next wireless technology for communication with high data rate, high capacity and will tackle energy efficient operation in the near future [2]. To design an individual antenna is easy, but data rate will be low. The present/next technology requires high data rate, which depends on the multiple antenna systems called multiple input multiple output (MIMO) [3,4].5G technology will resolve almost all drawbacks of 4G technology in future and will provide data rate up to three times of 4G, and the main advantage of 5G is that mobile device with 4G can be upgraded to accommodate 5G antennas [5]. In wireless communication systems, it is required to separate the desired signal from the interference signal. By reducing the multipath and channel interference, smart antennas will provide high capacity of signal transmission in wireless communications [6][7][8][9].The design of butler matrix is one type of passive beamforming network which consist of N input and output ports and N input and output antenna elements to produce N principal orthogonal beams at different directions. The operation of butler matrix design can be understood as: Firstly, radio frequency (RF) signal will get excitation from the input ports, after that signal will go to the output port through the feeding array elements. The signal will propagate equally with a constant phase between them, and beam radiation will generate at a certain angle [10][11][12].