چكيده به لاتين
In this project, a two-step technique for design of planar array is used. In the first step, the planar continuous current source is synthesized and then in the second step, this synthesized source is discretized. The purpose of the planar continuous current source synthesis is to determine the current distribution which generates the desired radiation pattern that in this project method of moments and method of least squares for this purpose are used. At first, the relation between the desired radiation pattern and current distribution is extracted in an integral equation form and then the solution domain is divided into several segments that current distribution is expanded into a set of pulse basic functions, Therefore, the integral equation turns into a discrete equation that by applying weighting functions corresponding to the method of moments and method of least squares, a linear equation system is obtained. So the current distribution is determined by solving this linear equation. To obtain the appropriate values for synthesis error and Superdirective ratio, the number of segments should be selected appropriately, which is discussed about it. In the second step, for design of planar array, the synthesized planar continuous current source is discretized and values of sidelobe level, ripple, and dynamic range ratio are calculated. If the values of sidelobe level and ripple are desirable, some of the array elements with low excitation amplitude are removed. If the values of sidelobe level and ripple are not desirable, so elements excitation should be optimized that two methods for optimization are used. The first method is minimizing a suitable cost function and the second method is iterative method of least squares.
