Comparative Analysis of UHF-Horn Antenna Sparse Structures Characteristics at Different Frequencies

The size and weight of antennas operating in the UHF-band are relatively large to provide effective signal transmission and reception. Reducing them while maintaining the antenna performance is important for various applications. The recently developed Optimal Current Grid Approximation approach and its modifications can be used for this purpose. However, the sparse structures they generate are subject to the fact that the current distribution in the wire grid structure differs at different frequencies in the operating frequency range. Therefore, this paper analyzes the effects on antenna performance after generating its sparse structure at a particular frequency by applying these approaches to a wire-grid structure approximating the metal surface of a horn antenna operating in the UHF band. Different sparse structures are generated based on the current distribution in the original wire-grid structure at 0.7, 0.915, and 1.3 GHz. Their antenna characteristics dependences on Grid Element Elimination Tolerance are compared with each other and with those of the original structure. In addition, the characteristics of some sparse structures generated after applying different approaches with specific Grid Element Elimination Tolerance values are analyzed and compared with those of the original structure in the operating frequency range. Based on an evaluation of the advantages and disadvantages of each sparse structure, this paper provides recommendations to enable manufacturers to select the frequency at which they can generate sparse structures that meet their requirements and the approach that should be used to achieve this.