Study On Theory And Design Of UWB Antenna For 3G Communication

Communication equipment with high-capacity, high-quality, and high-security is becoming more and more important during the rapid development of mobile communication in past several decades. Meanwhile, the large number of newly emerged standards and technologies for wireless applications have greatly promoted the development of related industries. Therefore, communication facilities must be developed with high standards to meet the increasing requirement of communication system. In mobile communication systems, small-sized wideband antennas are designed as core components, so that communication facilities with smaller size and higher frequency range must be developed. Therefore, it is of great significance to make a profound study and research on the miniaturization wideband antenna.In this paper, the basic theory and several typical analysis methods of the antenna were introduced. Then, the development direction, especially its theory and existing technology of ultra-wideband(UWB) antenna with miniaturization and wideband was presented,. In addition, four kinds of methods for prepare broadband antenna were studied by detailed presenting their theory, and the application of those methods in the design for antenna were also summarized here. In the last part, the author designed a new antenna with quasi-fractal structure, and this new antenna has been simulated by Ansoft HFSS software. From the original design to the analysis of the final simulation results, two wideband technologies have been used in this part. At the same time, based on fractal structure, and an angle was cut, the shape of the antenna is hexagon. By adjusting the antenna model, we finally got its gain more than 6.9d Bi, which was higher than general antenna; and the relative bandwidth of antenna is 10.78%, which shows good radiation directivity. It is a quasi-fractal antenna with high gain which can be used in RFID, the mainly working frequency of it are 2.45 GHz, 4.83 GHz and 8.88 GHz, respectively(i.e., multiple frequency). In summary, this research not only broadened the bandwidth of antenna, but improved its performance as well. It has a great practical value.