Research On Conformal Leaky Wave Antenna

With the expansion of wireless communication applications,the application environment is becoming more and more complex.As an important part of supporting wireless communication,antenna also needs to adapt to different application environments.There is a kind of antenna which needs to be attached to the surface of the carrier to reduce the wind resistance.This kind of antenna is called conformal antenna.The existing conformal antennas usually use patch antenna as the basic element.Its complex feed network will not only increase the design difficulty,but also increase the antenna volume,which is not conducive to meet the requirements of conformal and miniaturization.In this paper,according to the development needs of conformal antenna,the conformal antenna based on leaky-wave antenna(LWA)is studied,which provides a new kind of antenna structure and corresponding theoretical and technical support for the design of conformal antenna.The main work and innovation of this paper are as follows:1.Two kinds of conformal LWAs based on different waveguides are proposed for cylindrical carrier.One is cylindrical conformal LWA based on cavity waveguide.The transmission characteristics of this waveguide are basically the same as those of rectangular waveguide with the same structure parameters;The results show that the antenna can achieve omnidirectional radiation when integral period number are transmitted in the waveguide.On this basis,considering the actual processing problems,a cylindrical conformal LWA based on substrate integrated waveguide(SIW)is proposed,which improves the feasibility of antenna processing while ensuring the same radiation characteristics.A resonant cavity feeding structure is designed for cylindrical conformal LWA.The energy in the resonant cavity is coupled to the radiation layer by the coupling slots to realize impedance matching.2.A conformal SIW LWA is proposed for conical carrier.The transmission and radiation characteristics of conical conformal SIW LWA are analyzed,and its structure design method is summarized.The results show that the antenna can radiate conical beam when integral period number are transmitted in the waveguide.The equivalent waveguide width of the conical SIW is slightly wider than that of the straight SIW.The waveguide width can be adjusted appropriately to achieve the same transmission characteristics.3.Two kinds of conformal SIW LWAs with different slot arrangements are proposed for arc carrier.Firstly,the transmission characteristics of the arc-shaped SIW are studied.The results show that the structure has similar transmission characteristics to the straight SIW.On this basis,An arc conformal SIW LWA with a series of uniform slot is proposed,which can achieve high radiation efficiency.Secondly,based on the annular array theory and traveling wave theory,the radiation field calculation model of arc array is established.Based on analysis of the model,the design method of arc conformal SIW LWA with directional radiation is proposed.Through the actual processing and test verification,it shows that the proposed antenna can generate directional beam.It provides an effective solution for the directional wireless communication of the carrier with curved surface.