The Research On The Double-frequency Microstrip Slot Antenna

With the rapid development of wireless communication technology, spectrumresources become more and more strained. The bandwidth and transmission rate of original802.11b (2.402GHz~2.480GHz) agreement is very limited, which can not meet today’sdemands any more. Because of higher frequency and more abundant spectrum resources,802.11a (5.15GHz~5.35GHz) agreement is playing an increasingly important role in datacommunication. This demands that the antenna of a transmitter can not only work on twodifferent bands, but also should be small, light and low cost.Based on deeply study of the theory of microstrip antenna, slot antenna theory anddual frequency antenna theory, an ordinary dual-frequency slot print antenna is improved.In order to achieve a perfect matching state, a fan-shaped,which can adjust the inputimpedance is added on the top of the microstrip feedline. Besides, a large ground is placedunder the antenna so that the gain can be improved greatly. In order to meet the designdemands, every parameter of this new antenna is discussed in details, and at last a groupof ideal parameters are achieved. According to these parameters, an antenna type isfabricated and measured results show that the measured result as the same as simulationresult. An antenna can be well used at2.4GHz and5.2GHz.There are four parts compose in the thesis. First we state the background andsignificance of the study of microstrip slot antenna and simply introduce four kinds ofsimulation software in electromagnetic field.Here we used Ansoft HFSS as mainsimulation software.Second, the basic theory of microstrip antennas, slot antennas anddouble frequency antennas as well as some electrical parameters are explained. Third, anovel structure of double frequency slot antenna is proposed. And its parameters aredetailedly researched under the help of HFSS.Finally, we obtain a group of parametersthrough optimization,these parameters make the antenna wok perfectly on2.4GHz and5.2GHz. And according to these parameters we fabricate a sample, which measured resultsdedicate that it coincides to simulation.