Novel Concept of Projected Polyhedron to Generate Quasi-Periodic Array Lattice for SLL Improvement in Beam Steerable Array Antenna

This paper presents the new concept of the projected polyhedron to produce quasi-periodic array lattice, which provides an improvement in peak sidelobe level (SLL) during beam scan. Quasi-periodic array lattices generated by projection of vertices of the single dodecahedron and co-centric dodecahedron and icosahedron on aperture plane, have been discussed in detail. 3-axis rotation and scaling of polyhedrons are used to design quasi-periodic array lattices. Recently developed Jaya algorithm has been employed to optimize the farfield performance of array antenna. The rotation angles and scale factors of polyhedrons are used as optimization variables and the objective function is defined to improve peak SLL while maintaining the minimum inter-element spacing. Both types of quasi-periodic array lattice have been modeled, designed and optimized. Array analysis of the same has also been carried out for ± 30° beam scan and analysis results are discussed in detail. 5.0 dB and 4.2 dB improvement in the peak SLL has been achieved for array lattice with single and co-centric polyhedrons respectively. Performance of polyhedron based array lattice has also been compared with Pinwheel type quasi-periodic array lattice, for comparative assessment.