Research And Design Of Left-Handed Metamaterial Lens Antenna

With the rapid development of technology in the field of telecommunication,there is an increasing demand for antennas with high gain,small size and low cost.Research and development of high gain,high orientation,low profile,planar integrated lens antenna now has important theoretical and practical significance.Left-handed metamaterials are composite structures with extraordinary electromagnetic properties which cannot be found in natural materials.In consider of the unique electromagnetic properties of the left-handed material and the design advantages of the Fabry-Perot resonant cavity antenna,this thesis proposes three new planar lens antennas which significantly improves and enhances the performance of traditional antennas.The main researchs and in this thesis include the following three aspects:(1)The basic theoretical part of this thesis is the work principle of the left-handed metamaterial unit structure and its resonant working conditions.Based on basic theories,a planar left-handed material unit with one-side etched counterpart resonant ring is designed.With the ring-shaped metal wire on one side of the dielectric substrate,the material's permittivity and permeability can be simultaneously negative at the working band.The left-hand cell is periodically arranged to form a cover placing above a normal patch antenna to form a planar lens antenna working at 16.4 GHz with a gain increment of 4.4 dB.(2)In this thesis,a Fabry-Perot resonator antenna with slot-coupled square linearly polarized microstrip antennas as the feed-in is proposed as a left-handed lens antenna feed.The array of the left-handed units is arranged closely with the radiation aperture of the Fabry-Perot antenna to form a left-handed lens antenna.By optimizing the design,the highest antenna gain reached 21.5dB,increased 8.4dB,3dB beam width decreased from 43.9 ° to 11°.Moreover,the direct coverage of the left-handed lens preserves the low profile benefits of the F-P resonator antenna.(3)By separating the feed and the partially reflecting surface of the co-designed Fabry-Perot resonator antenna,the left-handed unit array and the partially reflective surface can be combined into a double-layer structure lens to improve the antenna radiation performance.In this thesis,the left-handed metamaterial structure is applied to the design of Fabry-Perot antenna,which realizes the dual-frequency operation and has a certain electric-small antenna effect.Compared with the traditional Fabry-Perot antenna,the working directionality of the lens antenna in dual frequency bands is good,and the double-layer lens structure is closely connected,which reduces the processing difficulty.