Digital Phase Shifter-Based Null Steering in Half-Wave Dipole Phased Arrays for 5G/6G Using an Enhanced Rüppell’s Fox Optimizer

Finite-resolution phase-only antenna synthesis is a constrained, multimodal combinatorial search problem in which small changes in digital phase codes can substantially alter interference suppression. This study applies the Enhanced Rüppell’s Fox Optimizer (eRFO) to null steering in a 20-element linear array of half-wave dipoles with fixed half-wavelength spacing and unity excitation amplitudes. The bioinspired search framework combines exploration and exploitation with adaptive control, chaotic diversity, opposition-based learning, and local refinement; candidate evaluation is restricted to feasible digital phase states. Conjugate-symmetric excitation reduces the number of independent optimization variables from 20 to 10. The radiation model combines the array factor with the isolated half-wave dipole element factor. Numerical examples examine sidelobe control, single and multiple point nulls, 4-bit and 8-bit phase resolution, and angular sector-null suppression. The reported 8-bit single-null case reaches −93.48 dB, while the dual- and triple-null cases place all prescribed nulls below −91 dB and −92 dB, respectively. The 4-bit single-null example reaches −73.64 dB. For the angular sector-null case from 11.75° to 16.75°, eRFO attains a maximum sampled level of −70.41 dB and is compared with genetic algorithm (GA), differential evolution (DE), and particle swarm optimization (PSO) solutions. Statistics over 50 independent runs, a mechanism ablation, a deterministic benchmark with a posteriori quantization, and sensitivity analyses under random excitation errors and mutual coupling complement these idealized single-frequency results. The contribution is the adaptation of bioinspired search to a discrete electromagnetic design problem, with explicit trade-offs among null suppression, sidelobe control, and phase resolution.