The Research Of Novel High Gain Antenna Based On Transmission Enhancement

With the rapid development of wireless communication,a miniaturization,low cost and high gain antenna become more and more important in the communication system,and how to improve the gain of antenna becomes a difficult subject.Traditional methods to improve the antenna gain are:designing the array structure on the antenna surface,or adding coverage on the back of the antenna.In recent years,there are also establishing the appropriate structure on the metal layer of antenna,the enhanced effect of electromagnetic waves will be greatly enhanced,so as to improve the gain,this design of antenna based on the principle of transmission enhancement has gradually become a hot spot.In this paper,through studying and analyzing the theory of enhanced transmission and similar Fabry-perot cavity principle,the array structure and the cover layer structure are set on the metal layer of proposed antenna,two high-gain waveguide slot antennas have been designed and fabricated,respectively.The results show that the antennas have good radiation characteristic.The main work of this paper is as follows:1 The radiation principle of the slot antenna and the mutual coupling between the gaps are analyzed by using methods of A.F.Stevenson and Hung Yuet Yee,which provides the theoretical support for design module.2 The enhanced transmission phenomena of the plasma model,evanescent wave model and resonant cavity model are analyzed respectively,the resonant theory of resonant cavity is studied further,through the research on the thickness?length and location of cavity,we can see the transmittance of the gap is reduced when the position of the resonator is improved,,and increasing thickness and length of the cavity can increase the transmittance.3 Combining with the theory of enhanced transmission and similar F-P cavity,by adding an overcoat layer on the outside of the antenna,a high-gain waveguide slot antenna is designed.Compared with the traditional antenna,the gain of proposed antenna has been improved a lot,which can reach to 11dB in center frequencies of 10.9GHz and 13.7GHz?4 In order to reduce the volume of the antenna further,another kind of slot antenna has been designed,by designing the array structure on the upper layer of the metal plate,the gain of proposed antenna has reached to 12dB in center frequencies of 12.7GHz and 15.0GHz,the thickness of antenna reduced almost half,which has an advantage of low profile relative to the traditional flat-panel antenna.