Effects of Spacing and Number of Elements on the Fields Radiated by Linear Arrays of Equally Spaced Elements

Abstract

This paper examines the effects of spacings and number of elements on the radiation features of linear antenna of uniformly spaced elements, oriented in end fire directions. Use is made of pattern multiplication concept to evaluate the electric field radiated by the antenna when excited with sinusoidal current distribution. It is found that, when the spacings between the elements of the array are , and , respectively, the radiated field patterns of models of the array depict radiations in broadside and end fire directions while at lower spacings of and , radiations exist only along the end fire directions. In addition, it is also observed that, the beam-width of the main lobe of the field patterns reduces as the spacing and number of element increase which suggests better directivity. However, the improvement in the directivity is followed with side lobe levels which seem to be the disadvantage of that benefit. Furthermore, it is discovered that the array factor patterns and radiated electric field patterns of the antenna display characteristics that are largely similar.