Some studies on arrays for sidelobe reduction required for EMI control

Arrays are used to obtain high gain and directivity. The design of such arrays depend upon the excitation, spacing, orientation and type of radiating elements. Different types of radiation patterns are required to be generated depending on the application. The radiation patterns usually contain one main beam and a few sidelobes. Ideally the sidelobe levels should be as minimal as possible. However, depending on the type of design of the array, sidelobes of considerable levels exist. The presence of high level sidelobes are undesirable and produce EMI problems. In view of this, it is required to design array antennas which can generate the radiation patterns with low sidelobe levels. Some investigations on the methods of array design are carried out in this paper to produce low sidelobe radiation characteristics. The methods involve the design of amplitude distribution, phase distribution and space distribution functions. Some of the standard amplitude distributions and space distributions are considered and the radiation patterns are computed