Edge-Sparsing and Two-Level Tapering to Reduce Sidelobe Level in Small Square Antenna Arrays

This paper describes a method for synthesizing a small square antenna array with a low sidelobe level (SLL). The process is based on a small square antenna array of 12 elements × 12 elements with a size of $6 \lambda \times 6 \lambda$ and 8 elements × 8 elements with a size of $4 \lambda \times 4 \lambda$. Then, the square aperiodic is roughly half-filled with approximately in-fill thinning of $55.55 \%$ and $50.00 \%$ in the planar element arrangement of 12 elements × 12 elements and 8 elements × 8 elements. In the uniform amplitude the value $I=1$, however in the two-level tapering of the small square antenna array 12 elements × 12 elements using a polynomial equation of degree two so the values $I_{1}\lt 1\lt I_{2}$. Meanwhile, the 2-level tapering of the 8 elements x 8 element small square antenna array uses the I value obtained from the Hanning Window method. Moreover, an interesting feature about two-level tapering approach in small square antenna array is proposed in this paper. With this design, sidelobe levels is lower than -21 dB in the $\mathrm{Phi}=0^{\circ}$ direction and lower than -17 dB in the $\mathrm{Phi}=45^{\circ}$ direction can be achieved.