Design Of Novel Dual-band Antenna And Ultrawideband Antenna

Compared with the traditional antennas, microstrip antenna has many advantages, such as smaller volume, lighter weight, lower profile. Besides of these, microstrip antenna is easier with carrier type and easier to implement multiple frequencies etc. Microstrip antenna is widely used due to these advantages. However, the performance of the traditional antenna is difficult to meet the needs of communication system because of the progress of communication technology. It has become a hot topic to make a dual-band antenna and broadband antenna. The basic technology of microstrip antenna such as miniaturization, dual-band and broadband technology is proposed in this paper.Two kinds of microstrip antenna with new structure are presented in the whole paper. The first one is a dual-band antenna which has a circle shape on its radiating surface with DGS structure on the ground. After optimization, the antenna can work at 5.4 GHz to 6.3GHz and 7GHz to 10.6GHz.The lower frequency band coveres the IEEE 802.11 working frequency band. The relative bandwidth reached at 42.7% in the higher frequency band so that it can meet the need of engineering requirements in the future. Another one is designed based on the previous one. This one can be used in the ultra-wideband (UWB) communication system. Firstly, add the D-shaped DGS structure on the ground. After optimization, the size of the antenna reduced and the working frequency band of the antenna broadened. Secondly, add the periodic structure on the ground. The working frequency band of the antenna further broadened, and the antenna pattern improved. Finally, the working frequency band of the antenna is 3GHz to 12.2GHz, the antenna pattern is stable in the whole band, it shows good performance as a UWB antenna. The physical antennas were processed, the mesasured results show consistent match with the simulated results.