Research Of Miniature Multi-band Microstrip Antennas

In recent years,great interest was focused on microstrip antennas for their small volumes,low profiles,good integration,low costs and good performance.With the continuous growth of mobile communication service and the constant miniaturization of communication equipment,there are higher and higher demands for the volume of antennas,integration and working band.The main task of this thesis is to design and study the miniature multi-band microstrip antennas.In this thesis,the author summarizes the theoretical analytical methods of the miniature multi-band microstrip antennas.With the aim of implementing the characteristic of the miniature multi-band microstrip antenna,the author has done some researching work in several different aspects:First,the miniature and multi-band micro-strip antenna techniques are studied. The feasibility of new miniature multi-band microstrip antennas combined with several techniques is proposed.Second,a new method for designing a triple-band microstrip patch antenna is presented.By etching two asymmetrical narrow slots close to the radiating edges of a rectangular patch,the antenna shows similar radiation designed properties at three resonant frequencies and achieves tri-band operation.A tri-frequency antenna is designed and simulated.The tri-frequency antenna can be operated at the centric frequency respectively f_L=2.15GHz,f_M=2.93GHz,f_H=3.50GHz.Finally,by using the simulation software,the influence on the centric frequencies is studied by changing the antenna's parameters such as the feed,the width of the left-slot,the position of the left-slot,and the length of the slots.Thus the laws of the variety are proposed.The achievements of physical models and principle analysis can be applied in the design and research of new microstrip antennas in the future.