Design of an improved high-gain omnidirectional printed dipole antenna

摘要

This letter proposes broadband hign-gain omnidirectional printed dipole antenna unit, and a 1×2 array is designed and fabricated. The radiator of the antenna is a structure of half-wavelength dipole resonant. The antenna array is fed by a phase-shifting microstrip power divider network which is designed conformally with the middle ground. As we know, microstrip feeding is unbalanced, a metal shielding sleeve is introduced to achieve balanced feeding of the dipole. And the metal shielding sleeve also have a function of improving the operating bandwidth of the antenna, and stabilizing the structure. The measured 10dB return loss bandwidth is about 36% (1 GHz ∼ 1.45 GHz), and the gain of the array is greater than 4.7dBi, and the out-of-roundness is less than 2.1 dB over the entire band.