The Design Of UWB Antenna With Notched Band Characteristic Using HFSS And Genetic Algorithm

Due to the rapid development of wireless communications technology, moderncommunications present higher requirements of information storage, data transmission rateand confidentiality, to accord with it, the ultra-wideband (UWB) communications are widelyused. Applications of UWB communications present more challenges for antenna design,which requires the antenna to own the bandwidth from3.1GHz to10.6GHz. At the same time,the band-notched characteristics are indispensable for reducing the potential interference fromsome narrow-band systems.The antennas’ structure is becoming more complicated as they require higherperformances. The traditional antenna design techniques have a lot of shortcomings such aslow efficiency, long design time, relying on engineers’ experience, which can’t satisfy therequirements of antenna design. The automated antenna design method based on HFSS andgenetic algorithms is expected to solve these problems.The thesis will do some exploration on the optimization in three Ultra-widebandantennas with band-notched characteristics. The first one is a meshing rectangular UWBantenna. The existence of small rectangles can be decided by the genetic algorithm，whichachieves the goal of optimizing rectangular patch. This antenna’s reflection coefficientbetween3.1GHz to11GHz is less than-10dB and it has5.25GHz~5.8GHz stop band.The second is a Cantor Set Fractal UWB antenna with a notched band characteristicusing U-Shaped parasitic element. Its bandwidth covers from2.95GHz to11GHz. Theparameters of the parasitic element are optimized by GA to reduce the interference of WLANand X-band.The last one is a circular UWB notched band antenna with the slot，and the antennaimpedance bandwidth covers the entire UWB. The position and size of the slot are optimized，making the antenna to have different stop bands to avoid the interference from WLAN,WiMAX and X-band.They prove the feasibility and validity of optimization design based on HFSS andgenetic algorithm for antennas.