Design And Analysis Of An Antenna Far-Field Measurement System

Accurate and rapid antenna measurement technique has become an indispensable tool for the development of various types of modern antenna research. In this paper, we depict the basic principle of the antenna far-field measurement and describe the construction and analysis of the entire measurement system in detail according to the project targets. There have rapid test speed, high precision and easy installation antennas in this system, so it will have a good prospect in the field of mobile communication antenna test. The following are the research results achieved in this article:1. According anechoic chamber design experience abroad, we select the rectangle darkroom which is suitable for the project test. This paper presents the performance of the darkroom and carries out a detailed analysis for proving to be the reasonable performances. For the design of darkroom, the paper plus a special absorbing wave ridge structure in the middle of darkroom, which is used to reduce the reflected wave and improve the performance of the darkroom. The simulation results show that the size and design of the entire structure meet the design requirements.2. The system is divided into transmitter subsystem, turntable subsystem, control subsystem and radio frequency subsystem, and the paper analyze and describe the principle and function of each part. According to the actual demands for all types of test antenna, the system have seven movable shafts. The control system will complete the precise positioning of the turntable and control of vector network analyzers, and the system can measure the multi-port antenna fast through sweeping multi-channel technology. The gain of standard antenna is calibrated through the three-antenna method, which can ensure the accuracy of the antenna gain measurement. Then the article analyzes the pattern measurement and gain measurement error with detailed formulas given.3. With the basis of conventional horn antenna design, the article clarifies the meaning of broadband technology and designs a pair of double-ridged horn antenna over the frequency band 0.5-6GHz in the high-frequency electromagnetic simulation softwareHFSS, which make use of the principles and methods of the ridge wave-guide theory. Through the software optimization, we have optimized the ridge structure of the antenna, the wave-guide cavity and the feeding section, so the pattern of antenna, gain and VSWR meet the design requirements. Finally, it is found that all the parameters have a more good consistency after comparison the measurement results with the simulation.