Analysis of circular array of monopole on the ground plane radiating linearly polarized conical beam for wireless LAN applications

An analysis of a conical beam antenna using circular array of monopole on the ground plane is presented. This antenna was proposed for application to the HIPERLAN system. The structure of this antenna type is simple and easy to fabricate. The radiation pattern of the antenna is calculated by combining the total fields radiated from each monopole on the ground plane. The effect of the finite size ground plane is taken into account and found that it affects the back lobe level. Moreover, it is apparent that a nondirectional azimuthal pattern is realized when the circumferential spacing is sufficiently small. The radiation patterns for various parameters such as the array radius and the number of elements are demonstrated. Antenna measurements are set up to verify the proposed principle. The theoretical and experimental results are in good agreement.