P.L. Batov, N.V. Drozhzhina, I.E. Kalashnik, A.E. Tumanskaya

During the AESA designing it was decided to use vertical and horizontal beams. These beams divide antenna curtain to subarrays. Such decision allows us to increase soundness of construction and to lighten the installation and simplification of array modules replacement. Because of this it was necessary to research how design features affect the directivity pattern. The new algorithm allowing us to assign amplitude and phase distributions on antenna array in the form of blocks (so-called modular or slab distribution) was added into integrated software (IS) "LambdaMDS". Three variants of beams disposition were considered: three vertical, three vertical and one horizontal, three vertical and seven horizontal. Modeling with IC "LambdaMDS" showed sizeable increase of sidelobe level in the presence of beams. It is the result of interference from subarrays. Therefore it was proposed to use conducting metal fixing bolts. These fixing bolts were substituted for some upper and lower radiating elements in antenna module. So horizontal beams stopped to be solid. It was shown after modeling that separate fixing bolts almost do not affect on directive pattern in horizontal plane, and the sidelobe level in vertical plane decreases. Nevertheless, findings did not satisfy directive pattern requirements. As a consequence of modeling it was decided to reduce number of metal beams in spite of serviceability of such array antenna divided into subarrays. In view of the aforesaid it was made a decision to use three vertical beams without any additional fastening changing array antenna geometry.