Nowadays, the development of sparse antennas with lower mass to replace conventional ones while maintaining their performance is an important challenge to meet the requirements of modern wireless communication systems. The creation of sparse structures after applying the recently developed Optimal Current Grid Approximation approach and its modifications is subject to the fact that the current distribution in the wire grid structure differs at different frequencies in the operating frequency range. Therefore, this study is devoted to a comparative analysis of the characteristics of sparse structures obtained at different frequencies in the operating frequency range derived from wire grid approximation of the metallic surface of a conical horn antenna operating in the C-band. Current distributions obtained at 5.3, 5.8, and 6.3 GHz were chosen to generate the sparse structures. The antenna characteristics of these structures are compared with each other and with those of the original structure. In addition, this study shows the performance of various sparse structures in the operating frequency range in detail and compares them with the original structure. The advantages and disadvantages of each structure are discussed and valuable recommendations are provided. The results of this study will help manufacturers choose the right approach and frequency to create sparse structures for specific requirements.