2025-09-09
Improved Low Sidelobe Pattern Synthesis of Planar Arrays Having a Distorted Triangular or Rectangular Lattice Due to Row Displacements
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Progress In Electromagnetics Research B, Vol. 115, 110-119, 2025
Abstract
This paper describes how the low sidelobe pattern synthesis of planar arrays with a distorted triangular or rectangular lattice, caused by row displacements, can be improved using the iterative Fourier transform (IFT) method. Array antennas with a rectangular, or triangular lattice combined with row displacements have an array factor that lacks periodicity in cosine u-v space for the u-direction. This means that for the u-direction, the pattern synthesis using the IFT method is limited to far-field directions that belong to the rectangular sector of the array factor computed by the inverse 2D FFT. Missing far-field directions in the pattern synthesis occur when the width of the computed array factor (AF) in u-v space is <2. In this case, not all far-field directions in visible u-v space are engaged in the pattern synthesis. The solution to this problem is to reduce the inter-element spacing along the rows with a factor two by including dummy elements with zero excitation between the active elements in each row. In this way, the width of AF, computed by the inverse 2D FFT, is doubled in u-v space. This doubling will result in twice as many far-field directions in the u-direction being involved in the pattern synthesis. After successful synthesis, all dummy excitations are removed from the synthesized set of excitations. The element excitations thus obtained, without the dummy ones, still perform the same as the original excitation obtained from the pattern synthesis. Three examples will demonstrate the validity of this solution.
Citation
Will P. M. N. Keizer, "Improved Low Sidelobe Pattern Synthesis of Planar Arrays Having a Distorted Triangular or Rectangular Lattice Due to Row Displacements," Progress In Electromagnetics Research B, Vol. 115, 110-119, 2025.
doi:10.2528/PIERB25061304
References

1. Keizer, Will PMN, "Fast low sidelobe pattern synthesis of planar arrays having a distorted triangular or rectangular lattice due to row displacements," Progress In Electromagnetics Research M, Vol. 132, 85-94, 2025.
doi:10.2528/pierm25010203        Google Scholar

2. Keizer, Will P. M. N., "Low sidelobe pattern synthesis of array antennas with a triangular or skew lattice using the IFT method," IEEE Open Journal of Antennas and Propagation, Vol. 4, 1000-1015, 2023.
doi:10.1109/ojap.2023.3322330        Google Scholar

3. Mailloux, Robert J., "Wideband quantization lobe suppression in arrays of columns for limited field of view (LFOV) scanning," 2015 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting, 2453-2454, Vancouver, BC, Canada, Jul. 2015.
doi:10.1109/aps.2015.7305615

4. Wang, Hao, Da-Gang Fang, and Y. Leonard Chow, "Grating lobe reduction in a phased array of limited scanning," IEEE Transactions on Antennas and Propagation, Vol. 56, No. 6, 1581-1586, Jun. 2008.
doi:10.1109/tap.2008.923354        Google Scholar

5. Zeng, Yu, Xiao Ding, Xiang-Lin Ye, Filippo Costa, Giuliano Manara, and Simone Genovesi, "A general analytical arrangement for large-spacing planar scanning array grating lobe suppression based on energy homogenization theory," IEEE Transactions on Antennas and Propagation, Vol. 72, No. 9, 7389-7394, Sep. 2024.
doi:10.1109/tap.2024.3433593        Google Scholar