Elements Reduction Using Unequal Spacing Technique for Linear Array Antenna

摘要

The basic idea of this paper is to use unequal spacing technique not only to reduce the side-lobe level but also to reduce the number of element of linear array antenna. The arrangements of the elements followed the arrangement given by R. F. Harrington and Y. T. Lo. Most of the simulation done by previous researches focused on the algorithm, where the mutual coupling effect contributed by the elements was not included. The simulation started with 16 elements rectangular micro-strip patch of linear array antenna with one half wavelength spacing between the elements at an operating frequency of 5.8 GHz, using FR4 substrate with dielectric constant of 4.6, and thickness of 1.6 mm using CST2008 software. The result obtained will be put as a reference and will be compared to the unequal spacing simulation. It will be followed by the simulation of unequal spacing antenna for both symmetrical and asymmetrical arrangement where the amplitude of the excitation is assumed to be constant. Under symmetrical arrangement, another two different arrangements that are space tapered and non-tapered were investigated. The simulation started with 10 elements and was increased until its performance equal or was comparable with the 16 elements equal spacing antenna. The simulations result shows that by using the unequal spacing technique, the linear array antenna has better potential to have fewer numbers of elements but the performance was comparable. In this paper, the number of element reduced from 16 elements to 13 elements with better side-lobe level, same half power beam-width (HPBW) value and produced comparable antenna gain.