DESIGN AND SIMULATION OF A PLANAR 4*4 BUTLER MATRIX IN MICROSTRIP TECHNOLOGY FOR X BAND APPLICATIONS

This paper presents the optimum design of a 4x4 planar Butler matrix array as a key component of a switched beam smart antenna system operating at 10 GHz for X band applications, with a dielectric substrate RT-Duroid of εr =2.2 and thickness of 0.79mm. In 4x4 Butler matrix, four input ports are used for the input signal connections and four output ports can be connected to an array of four micro-strip patch antennas to form the beamforming network. Such a network is capable of production of four orthogonal uniform beams (at −45◦, −15◦, 15◦ and 45°) with effective coverage over 100°, when feed with electromagnetic signals. Conception details, and simulation results are given for the components (hybrid coupler, crossover, phase shifter) used to implement the matrix

Design of High Directive Inset Feed Microstrip Triangular Patch Antenna with Dielectric Superstrate

The subject of enhancing microstrip patch antennas directivity, using either a frequency selective surface (FSS) or a double-negative (DNG) metamaterial slab, has been investigated by a number of researchers in recent years. The purpose of this paper is to show that we can also achieve the same goal by using a much simpler design for the superstrate, namely a dielectric slab. In this paper, we study the influence of dielectric superstrate on the performances of inset feed triangular patch antenna. This dielectric layer is disposed above the patch and both are separated by the air. The return loss, radiation pattern, directivity and VSWR are studied using HFSS software. The simulation results show that the gain, directivity and S11 parameter of the antenna with dielectric superstrate are increased significantly at X band (8-12GHz). Compared with the conventional patch antenna with the same size but without superstrate, the performance of the proposed antenna is improved obviously