In this paper, the authors were developed to present a rectangular cylindrical antenna, directive, for use in wireless technology. To obtain the results, simulations and analysis of the structure under study the program HFSS (High Frequency Structural Simulator) was used. This paper involves the study of electromagnetic fields of the wraparound antenna for use in rectangular cylindrical antenna for wireless. The antenna uses, as substrate, from rogers corporation. Numerical results for the resonant frequency as functions of the return loss and resonator length presented, considering the antenna diameter and the dielectric substrate. A good approximation of the measured results with the simulated was observed.