Research On Spherical Near-Field Measurement Technology

In recent years,with the rapid development of wireless communication technology,the role of antenna in the field of communication is becoming more and more important.With the increasing demand for high performance antennas,the rapid development of antenna measurement technology has been promoted.The development of the far-field antenna measurement technology is greatly limited because of the influence of the measuring field,electromagnetic environment and other factors,so people shift the focus to the near-field antenna measurement.The near-field antenna measurement can collect the near field data of the antenna under test,and obtain the far-field radiation characteristics of the antenna through the rigorous near-field to far-field transformation algorithm.It has the advantages of all-weather operation,small measurement field and high accuracy.Spherical near-field measurement,as one of the most important measurement methods for antenna near-field measurement,can provide the complete radiation characteristics of the antennas under test,and is suitable for all kinds of antennas.This measurement technology has become a hot research topic in the field of antenna measurement.In detail,the main research focus on the following issues:1.A new method to improve the measurement efficiency of the spherical near field measurement is proposed.In this thesis,the spherical near-field to far-field transformation algorithm and the three spline interpolation method are used to simulate the spherical near-field measurement.Compared with the simulation research that the former used three polynomial interpolation to improve the measurement efficiency,the three spline interpolation method can not only improve the efficiency of near-field sampling,but also guarantee the accuracy of transformation results.2.A correction scheme for the wide-band dual polarization antenna probe is proposed.In this thesis,a new wideband dual polarized probe has been studied deeply,and compared with the traditional rectangular open waveguide probe.After that,the probe is applied to the spherical near field measurement to achieve the efficient measurement of spherical near-field measurement.Finally,on the basis of the traditional probe correction scheme,a modified scheme for broadband dual polarization antenna probe is proposed in order to ensure the accuracy of the transformation results.3.In this thesis,the probe correction scheme is simulated and verified to explore the correctness of the correction scheme.Then in order to verify the feasibility of the probe correction scheme in actual engineering measurement,the spherical near-field measurement environment is built.And through the comparison of the transformation far-field results and the measurement far-field results to explore the practical application of the correction scheme.