Design of Omnidirectional Dipole Antenna Based on Lumped Balun Structure

In order to meet the demand for omnidirectional high gain antennas in base stations and wireless local area network applications, a design of an integrated printed dipole antenna based on lumped Balun structure is proposed. Firstly, a lumped Balun structure is designed according to the principle of a 3 dB bridge circuit, and the performance of the lumped Balun structure is verified by simulation software. The lumped Balun is composed of microstrip lines and lumped elements. After the input signal enters the Balun, signals with equal amplitude and 180° phase difference can be output from two output ports. Then, according to the principle of maximum transmission and minimum reflection, the dipole antenna is designed, and the lumped Balun is integrated with the dipole antennas printed on both sides of the dielectric substrate to complete the design of the Balun integrated dipole antenna. Finally, the optimal structure of the antenna is determined through electromagnetic simulation calculation and optimization, and prototype fabrication and measurement are carried out. The measured results show that the antenna can achieve horizontal omnidirectional high-gain radiation in the bandwidth range of 1. 35 GHz~ 1. 45 GHz. This antenna has the characteristics of light weight, low profile, and easy tuning, which provides a novel antenna structure for communication, broadcasting, and military system terminal antenna arrays.