Gain-Focusing Performance Evaluation of Nonlinear Frequency Diverse Arrays
DOI:
https://doi.org/10.13052/2026.ACES.J.410408Keywords:
Gain-focusing area, Nonlinear Frequency Diverse Array, single-point focusing, Two-point FocusingAbstract
Nonlinear frequency diverse arrays have attracted increasing attention because of their unique point-like focusing characteristics in the joint angle-range domain. However, the quantitative relationship between the focusing pattern and key design parameters, as well as systematic performance evaluation tools, have not been fully established. In this paper, we propose the gain-focusing area as a quantitative metric for assessing the focusing efficiency of nonlinear frequency diverse arrays (NFDA). Unlike conventional one-dimensional beamwidth measures, the gain-focusing area captures the joint angle-range behavior of the array and provides a basis for performance evaluation and design optimization. Using this metric, we systematically study single- and dual-region focusing, and quantify the influence of focusing location (angle, range) and array design parameters (number of elements, frequency-offset coefficient) on the gain-focusing performance. Numerical simulations demonstrate that the proposed gain-focusing-area based evaluation method provides a more reliable performance metric; compared with existing approaches, it nearly doubles the valid angular range while maintaining accurate characterization of the focusing behavior. This enables NFDA spatial focusing capability and parameter sensitivity to be robustly quantified over a wider field of view, offering a more dependable tool for shaping the electromagnetic environment in and around the target region.
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