Author_Institution :
Dept. of Electr. & Electron. Eng., Bahrain Univ., Isa Town, Bahrain
Abstract :
In order to eliminate the effect of clutter or jamming interference signals in the phased antenna array and, consequently, increase the signal-to-noise ratio, the sidelobe level of the antenna pattern should be made zero in the direction of arrival of these signals. The paper presents a new method for forming s in the directions of interference signals by controlling the positions of selected elements of the antenna array and, in turn, reducing the number of mobilized elements of the array. The technique involves two steps. In the first step, the contribution of each element´s position perturbation to the location is evaluated using the linearized method of small phase perturbations (Steyskal, H. 1983; Ismail, T. and Dawoud, M., 1991). The second step is used to select the elements of the array which contribute the most to the locations. Based on this selection, the new positions of the selected elements are calculated using a nonlinear programming technique (Chiba, I. and Mano, S., 1991). The results demonstrate the capability of this technique to form s in the required directions.
Keywords :
antenna phased arrays; antenna radiation patterns; antenna theory; array signal processing; interference suppression; nonlinear programming; adaptive sidelobe ing; antenna array element position; antenna pattern; clutter; jamming interference signals; mobilized elements; nonlinear programming technique; phased antenna array; small phase perturbations; Adaptive arrays; Antenna arrays; Chemical elements; Cities and towns; Clutter; Directive antennas; Equations; Interference; Phased arrays; Systolic arrays;