Theoretical Method and Analysis of Spherical Near-field to Far-field Transformation Based on Equivalence Principle

In this paper, a low-complexity near-field to far-field transformation (NF2FFT) method is proposed. The method employs Huygen’s and Schelkunoff principles respectively, and the difference lies in whether to adopt the equivalent electric current and the integral limitations. As an example, NF2FFT is implemented on a horn antenna. The calculation results show that the proposed method is a candidate solution to near-field antenna measurement.