Abstract

– Bi-cone wire antennas belong to the category of broadband wire antennas. It has been observed that these antennas suffer from low directivity, which limits their use in some applications requiring high-directivity antennas. In this research, a new method was proposed based on modifying the geometric structure of the bi-cone antenna to increase the directivity by adding director systems with a specific geometric arrangement. The bi-cone antenna acts as an active element, and the added director systems act as passive elements. The use of the director systems increases the directivity of the traditional bi-cone antenna due to the narrowing of the main lobe of the radiation pattern of the proposed structure in the horizontal E-plane. The effect of using the proposed structure on the shape of the radiation pattern in the H-plane was also studied in terms of the uniformity of the radiation pattern. The numerical study was carried out using a program designed based on the integral equations method, which is considered the most accurate method for the numerical analysis of wire antennas in the case of thin wire approximation. The designed program was compared with the well-known and internationally approved MMANA program, and the results were completely identical, confirming the validity and accuracy of the designed program. The designed program provides great ease and flexibility when constructing the antenna and changing its geometric parameters compared to the MMANA program. The effect of changing the geometric parameters and the shape of the director systems on the frequency and radiation characteristics of the proposed antenna was studied in order to identify the governing parameters that determines its behavior. The article presents extensive and detailed numerical simulation results that demonstrate the superiority of the proposed antenna over the conventional antenna in terms of directivity while maintaining the characteristic of wide-band frequency.