Use of plane wave decomposition for the analysis of interaction of the antenna and target in microwave introscopy

Localization of plane wave expansion using the method of quasisolution searching

“…However, for some problems the disadvantage of the plane wave expansion is its globality, since it is determined by the field spatial distribution along the full real axis [3,4]. On the other hand, the efficiency of this approach can be increased by going over to obtaining a spectral representation of the radiation field for a limited fragment of the aperture [5].…”

“…The problem of globality manifests itself especially clearly in the numerical implementation of the plane wave expansion for processing experimental data [4]. In this case, the plane wave spectrum (PWS) can be numerically obtained using a discrete Fourier transform (DFT), which involves the use of discrete samples of the field distribution, specified on a finite support [5].…”

“…In this case, the plane wave spectrum (PWS) can be numerically obtained using a discrete Fourier transform (DFT), which involves the use of discrete samples of the field distribution, specified on a finite support [5]. The size of the used interval is determined by the degree of divergence of the wave beam under consideration and the distance to the plane in which the transverse distribution of the field is supposed to be restored [4]. At small sizes of the secondary aperture, the size of the interval for the DFT of spatial distribution must be chosen many times larger than the size of this aperture, especially in the case of an asymmetric phase distribution on it.…”