The Study And Design Of CPW-Fed Compact Dual-band Antenna

The continuous development of antenna is becoming a new promote power of communication system changes. The application of intelligent antenna technology promotes the popularization of the third generation mobile communication technology, dual-band and multi-band antenna technology realizing the integration of systems and the mobile communication equipment miniaturized. So, the dual-band microstrip antenna which can work both for WLAN, WiMAX,WCDMA and other communication systems has been a important problem in the research of antennas.The basic theory of microstrip antennas is presented first in this paper. The analytical methods of microstrip antennas like the transmission line method, the cavity model method and the finite difference time domain method were studied, and each method was used to analyse the rectangular microstrip antenna with Matlab software. Based on the understanding of microstrip antenna’s radiation principles, the popular methods of design dual-band antenna were learned and summarized. The important part of this paper is the design of four novel dual-band antennas for different applications and the optimization research of proposed antennas with HFSS software.The first part of this paper proposed two dual-band antennas for WLAN/WiMAX and WLAN/WCDMA applications. The first model was based on the double T dipole antenna, with coplanar waveguide feed line replaced microstrip feed line to increase the bandwidth. The antenna size was reduced through bending two arms of T dipole. In order to meet the needs of the3G communication the second model was designed by increasing the low frequency part’s equivalent area of the first model. The simulation results confirmed the proposed two models have good multi-band character and compact structures which were convenient for manufacture and conformal.The second part combined the method of embedding stubs and inserting slots to obtain multi-band characters on the basis of rectangle ring and ring antennas. The antenna had simple structures, the stopband could be adjusted flexible by three grooves. The simulation results show that the proposed antenna can work within three band that met the requirements of WLAN and WiMAX applications. The omnidirectional radiation characteristics could be obtained.At last, we made out the summary of this thesis, proposed the problems encountered in the design and gave the direction of improvement.