volume | PIER Journals

Abstract

Two-way array factor is the product of array factors of transmitting array and receiving array in a radar antenna system. One of the major disadvantages of antenna arrays is undesirable high sidelobes near the main beam which causes ground clutter and interference in the radar system. Furthermore, increasing the number of array elements in transmitting/receiving modules results in a high complexity, cost, size, and weight. In this paper, a two-way radar structure with a receiving array that has only two elements is proposed to solve these aforementioned problems. Noticeably, all the existing receiving arrays have a number of elements that are much greater than two elements, and it is usually equal to or less than the number of transmitting array elements. Thus, this is the first time to produce such an extremely simple receiving array structure that has capability to provide low sidelobes and improved directivity in the resultant two-way array pattern. To demonstrate the flexibility and generality of the proposed two-way array structure, it is applied to the uniform array and non-uniform excitation array such as Dolph-Chebyshev as well as to electronic scanned arrays. Simulation results confirm the effectiveness and superiority of the proposed two-way structure where the highest sidelobe level reached -26.47 dB; the directivity was 25.96 dB; and the complexity of the receiving array was significantly reduced to only 12.5% when two separate non-existing elements were deployed and it was completely eliminated when two existing elements from the transmitting array were reused.

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Prof. Jafar Ramadhan Mohammed