Mutual coupling in finite arrays of rectangular apertures

Many antennas use rectangular array elements because of the versatile stacking geometry and the improved aperture efficiency they offer. This is particularly true in the field of radar antennas. Only with the availability of accurate array analysis, based on mutual coupling effects can realistic studies be made of some of the key radiation properties of radar arrays. For example the use of mutual coupling would permit the accurate prediction of embedded element pattern nulls. It is important to know the position of these nulls since they lead to blindspots in radar coverage. It is clear that the recent advances in the area of adaptive antennas will only be fully exploitable in the near future if accurate radiation characteristics of the array can be predicted. For example, such analysis permits the choice of optimum sub-array geometry permitting clusters of array elements to be combined to form the currently limited number of adaptive channels. The authors describe the analysis of the mutual coupling in finite arrays of rectangular apertures leading to an accurate model for the prediction of the radiation characteristics of these structures