Research And Design Of High Gain Antenna Based On Substrate Integrated Waveguide

With the rapid development of society,people's demands for information and the communication quality become higher and higher,and the high-gain antenna has shown potential application in many fields of communication and become one of the hot topics of antenna research.At present,the high-gain antenna has many types,such as parabolic reflector antenna,planar array antenna,leaky-wave antenna.Each kind of high-gain antenna has its advantages and disadvantages.For example,the traditional parabolic antenna has the advantages of simple feeding and high gain,but at the same time it also has the disadvantages of large volume,bulky,difficult integration and high cost;the planar array antenna has the advantages of easy integration and high gain,and the disadvantages of complex feeding network and large occupied area;the leaky-wave antenna has high gain,but its electrical length of antenna is relatively large,and it usually generates a conical beam,with low beam efficiency.The emergence of substrate integrated waveguide technology provides a new opportunity for the development of the high gain antenna.It not only has high transmission efficiency like the traditional waveguide,but also has the advantage of easy processing as a planar structure.In this dissertation,a parabolic reflector is designed which is based on the technology of substrate integrated waveguide,and it is employed in the design of a high-gain H-plane horn antenna and a planar periodic leaky-wave antenna.Simulation and analysis are executed,and the practical antenna is fabricated and measured.Compared with the traditional parabolic antenna,the design of this dissertation has the advantages of low profile and easy integration with planar circuits;and compared with the traditional planar antenna array structure,the complex feeding network is not needed in the design in this dissertation,and it has the advantages of simple feeding and miniaturization.The main works and innovations of this dissertation are summarized as follows:1.A parabolic reflector based on the technology of substrate integrated waveguide is proposed,and it is employed in the design of H-plane horn antenna.First,the merit of the parabolic reflector is that it can realize large radiation aperture and uniform phase distribution with simple feeding pattern,providing a prerequisite of realization of high gain.Second,the coaxial probe feeding combined with the reflective inductive post and the directive capacitive post is studied and the effect of the position relation between the feeding point and the parabolic reflector on the feeding is studied,and the optimal feeding structure parameters are obtained through optimization;Then the method of impedance matching between parabolic reflector and free space is studied,and the metal strips with metal post array are designed for matching,and it can greatly improve the matching degree between the radiation aperture and free space.Finally,for the proposed H-plane horn antenna based on the parabolic reflector,the field distribution inside the structure,the impedance characteristics and the far-field radiation characteristics are simulated and analyzed.The H-plane horn antenna is fabricated and tested,and the experimental results are in a good agreement with the simulation results.2.A one-dimensional beam-scanning high-gain planar leaky-wave antenna based on a surface wave structure loading with periodic metal strip array is designed,in which the parabolic reflector is used as a feeding structure.The influence of the antenna structure parameters on the antenna performance is analyzed in detail.3.A method of generating radiation null for periodic leaky-wave structures is proposed.This method is a Hybrid method of the mode expansion method and the effective radiation sections.First,the aperture field is decomposed into superposition of all space harmonics using the mode expansion method.Then,the effective radiation section of the radiation mode is calculated by the method of effective radiation section,and the radiation intensity of the effective radiation section corresponding to a certain direction can be suppressed by changing the structural parameters,and hence the radiation null can be generated.The traditional method of generating radiation null is suitable for the array structure or the continuous tapering aperture antenna.But in this dissertation,the method of generating radiation null for the periodic leaky-wave structure is proposed for the first time,and good results can be observed.