Study And Design Of Ultra-wideband Dual-polarized Antenna For Base Station

Base station antenna is an essential component of the mobile communication system. As well as its obvious function of providing a link between a base station and a mobile station, base station antenna is also an important device for many mobile communication applications, such as frequency re-use, diversity reception and coverage optimization. Each of the applications has its performance requirements to the base station antenna respectively.The vital problem of the mobile communication is how to using the limited spectrum resource to match the distribution of user demand in the space and time. In correspondent, many mobile communication systems are proposed. Inevitably, there are many mobile communication systems working at the same time. Thus, it is will be important to design an ultra-wideband antenna, which can meet the operational requirements of different systems or for the new systems in the future.First of all, the research achievements of wideband antenna so far are demonstrated in this thesis. And then the design of a novel ultra-wideband dual-polarized radiating element for base station is presented. HFSS, one of the electromagnetic simulate software, was employed to simulate the characteristics of this radiating element. According to the industry standard of base antenna, VSWR<=1.5 and isolation less than -28dB, the band width of this radiating element is from 1.4GHz to 3.6GHz. Secondly, the four- elements antenna array, which used the novel radiating element, was studied. The beam convergence property of the antenna array is discussed first. After the simulation, this thesis point out the normal single side-wall structure can not improve the beam convergence effectively. So a novel double side-wall structure is proposed. After simulation and adjusted the structure parameters, this thesis found an optimal structure. Finally, the concept of designing the base station antenna as a whole is demonstrated. All the base station antenna performance parameters at band 1710MHz~2170MHz were simulated and analysis. Considering the trade off of all performance parameters, including VSWR, isolation, beam-width, gain, F/B ratio and cross polarization ratio, the design of ultra-wideband dual-polarized base station antenna is realized at final.