Study And Design Of Wideband Slot Loop Omnidirectional Antenna

With the wide application of wireless communication technology and the rapid development of mobile communication,the application of antenna is becoming more and more extensive,and the performance requirements of antenna are becoming more and more strict.The bandwidth is the primary factor to be considered in research and design.In this paper,a vertical polarization slot loop omnidirectional antenna is designed with a frequency band from 1.7GHz to 2.7GHz for the application of modern mobile communication,and a four-unit array is set,which can be used for base station antenna System,Small Cell small base station system,indoor antenna distribution system and Wi-Fi antenna and other different scenes.The main work and achievements of this paper are:(1)The basic parameters of the antenna are introduced.The general design principle of the vertically polarized omnidirectional antenna is described,and the main factors influencing the gain ripple of the antenna are analyzed.(2)Based on the planar slot loop antenna,a three-dimensional three-element slot loop omnidirectional antenna element is designed.On this basis,an omnidirectional antenna with a bended structure is proposed,which further reduces the gain variation of the antenna and improves the antenna impedance matching,while achieving the miniaturization.Aimed at the bended slot loop omnidirectional antenna,the effect of each structural parameter on the performance of the antenna is analyzed,and the simulated and measured results are given.The measured results show that the antenna unit can achieve a voltage standing wave ratio less than 1.5 in the frequency band of 1.7GHz?2.7GHz and has a gain ripple less than 2dB in the whole frequency band.The unit gain is 2.4?3.6dBi.(3)A four-unit array is made of the slot loop omnidirectional antenna element,and a four-part power distributor is designed,and the symmetry is further improved by rotating 90°between each adjacent two units to reduce the gain ripple of the antenna array in the horizontal plane.The measured results of array can achieve a voltage standing wave ratio less than 2 in the frequency range of 1.7GHz?2.7GHz and has a gain variation less than 4dB in the whole frequency band.The measured gain in the frequency band is 5?6.3dBi.