Azimuthal Mode Decomposition Method for Cubical Surface Scanning With the Application to Spherical-Mode Field Synthesis

In this letter, a method of azimuthal mode decomposition is presented for cubical surface scanning. This method can be applied either in near-field-to-far-field (NF-FF) transformation in near-field antenna measurements or in synthesizing the fields using the virtual array principle. The method is presented for spherical-wave-mode field synthesis application in this letter. The method allows a reduction in the computational burden of the matrix inversion for synthesizing the fields. Requirements for the sampling locations on the cubical scanning surface and for the probe orientations and polarizations at each sampling location allowing the azimuthal-mode decomposition are provided.