Support vector regression is proposed to obtain the coupling matrix that accounts for the real behavior of an antenna array in the near-field multifocusing framework. The obtained model can then be easily included in this synthesis method in order to obtain the feeding weights which satisfy the radiation pattern requirements under real conditions. An example of the performance of support vector regression using information from method of moments is also provided to demonstrate the performance and accuracy of the technique. SUPPORT VECTOR REGRESSION, NEAR-FIELD MULTIFOCUSING, MUTUAL COUPLING
NEAR-FIELD MULTIFOCUSING FRAMEWORK UNDER REAL CONDITIONSThe aim of the NF-MF framework is obtaining the excitations to apply to the array elements so that the entire antenna focuses on the desired points simultaneously. Method explained in Reference [1] is used for this purpose, where an MP optimization or a PO synthesis of the feeding weights can be obtained according to the preferences of the application. Thus, excitations ! in (7) can be obtained using the NF-MF technique, with the following modifications to fulfill mutual coupling conditions.The commented synthesis technique in Reference [1] is based on a proper cost function defined by the maximum and minimum limits allowed for the field at each position of space, and its minimization is solved using an equivalent least squares problem and the Levenberg-Marquardt method [2]. A Jacobian matrix is then required, where some partial derivatives of the radiated field according to the