Experimental verification of methodology for generating sparse wire-grid antennas using the optimal current grid approximation

Problem statement. Traditional UHF-band horn antennas are typically heavy and bulky, which limits their application in systems with strict size and mass constraints. The transformation of solid metal antennas into wire-grid (WG) and sparse wire-grid structures has been shown to effectively reduce mass and wind load, but practical verification of the optimal current grid approximation (OCGA) methodology and its modifications for generating such structures remains insufficient. Aim. To summarize recently published and new results to provide a general OCGA-based methodology and to experimentally verify this methodology with different grid element elimination tolerances (GEET) to generate actual sparse WG horn antenna structures in the UHF band. Results. A pyramidal horn antenna operating in the UHF band was used to validate the proposed methodology. Various sparse WG structures were fabricated with GEET=5, 10, 25, 40% using OCGA and its modification. The experimental results showed strong agreement between the sparse and original WG structures in terms of reflection coefficient, gain, and radiation patterns. The generated sparse WG antennas demonstrated a mass reduction by 1.04–1.41 times relative to the original WG design and by 6.70–9.23 times relative to the solid structure, while maintaining acceptable performance. The wind load acting on the sparse WG structures was also reduced by 1.02–1.45 times compared with the WG antenna and by 5.25–7.45 times compared with the solid one. Practical significance. The proposed methodology enables the design and fabrication of lightweight, low-cost, and weather-resistant horn antennas without significant degradation of antenna performance. The results can be applied to various types of antennas and scatterers operating in different frequency bands, making the approach suitable for modern satellite, radar, and telecommunication systems where mass and structural resistance are critical.