Research And Design Of High Performance Single Offect Compact Range Reflector Antenna

In the millimeter wave,submillimeter wave and terahertz bands,the system of CATR(Compact Antenna Test Range)test method is one of the important means of antenna measurement.The system can generate plane waves to illuminate the antenna under test in order to obtain its electrical characteristics.The system of CATR does not need to use a large field,and can be deployed in an anechoic chamber that is not easily disturbed by the environment,which improves the convenience and accuracy of measurement.Therefore,more and more domestic and foreign scientific researchers begin to study the CATR test method.In this thesis,some key issues in the design of the traditional single offset reflector antenna with a single feed in CATR system are studied as follows:1.The electrically small CATR antennas with serrated-edges are studied.A certain band of CATR antenna was developed.The projection of the main body of the reflector is a circle with a diameter of 520 mm,which is designed with triangular serrated-edges,and an axially corrugated horn is used as the feed.It realizes a cylindrical quiet zone with a diameter of200 mm within a small reflector aperture,and the quiet zone performance meets the index requirements.The measured results show that the designed CATR antenna has good electrical performance,which is consistent with the simulated results.The antenna has been used in the simulation measurement system of a semi-physical missile in a research institute,and the effect is good.2.The large-aperture CATR reflector antennas with serrated-edges are studied.A system of large-diameter CATR antenna working in 1.7～110GHz is designed.The reflector geometry is offset parabolic,side-fed.A novel parameter-adjustable serrated-edges design is proposed to reduce the plane wave amplitude ripple in the quiet zone.The simulation software CHAMP and HFSS are used to optimize the pattern of the feed horns.The feed horns in each frequency band are axially corrugated horns,which have the advantages of wide beam,low cross-polarization and symmetrical pattern.The dual-linear polarization of the feed is realized by designing an ortho-mode transducer with a turnstile structure.The overall system is simulated and optimized by the commercial simulation software FEKO.Finally,within 36% of the reflector aperture,the quiet zone amplitude taper is less than1 d B,the amplitude ripple is less than ±0.5d B,the phase taper is less than ±2deg,and the phase ripple is less than ±5deg.The design results meet the requirements of technical indicators.3.Aiming at the problem of low utilization rate of the quiet zone of the single-reflector CATR measurement system with a serrated-edge,the design techniques of the CATR reflector with blended rolled edges are studied.Firstly,a method of optimizing the edge curve of the reflector combined with the genetic algorithm is proposed,and the optimized reflector model is established by using the three-dimensional drawing software Proe.Then,a wideband six-slot corrugated horn is designed as the feed,and its operating frequency covers 23.5～44GHz.Finally,the system of the CATR with blended rolled edges is analyzed,and the designed CATR antenna can effectively reduce the edge diffracted fields and greatly improve the utilization rate of the quiet zone.The simulated and measured results show that within 50% of the aperture of the CATR reflector,the plane wave amplitude taper is less than 1d B,and the phase peak-to-peak value is less than 10 deg.The effectiveness of the proposed optimization algorithm for the design of the reflector antenna with blended rolled edges is verified.