Simulation of planar near-field errors

摘要

When a planar near-field measurement is done, errors are introduced due to imperfections in the mechanical and electrical parts of the measurement equipment. In order to identify the characteristics of different types of errors, a MatLab program that simulates the near-field from an antenna has been developed. The near-field is transformed to far-field and the rrors are evaluated. This paper looks into fourdifferent error types: 1) Truncation errors (if the measurement surface is to small the near-field will be truncated before it reaches adequately low levels), 2) Probe-AUT distance rrors (fluctuations in the probe-AUT distance over the measurement surface), 3) Zigzag errors (due to data being acquired during both travel directions of the probe), 4) I, Q amplification errors (different a mplification for the I and Q chenanels in the receiver). The results are presented in plots which illustrate where in space the largest antenna pattern erros