On the Application of Sparse Spherical Harmonic Expansion for Fast Antenna Far-Field Measurements

The characterization of 3-D antenna radiation patterns is time-consuming. The field acquisition duration can be dramatically reduced by leveraging the sparsity of the radiated field spectrum into spherical harmonic basis. Only a small number of measurements points are then necessary to identify the few significant spherical coefficients describing accurately the antenna pattern. In practice, this compressed sensing-based procedure requires carefully chosen settings to work efficiently. The fitting to the data and the field sampling strategy are two crucial points in order to ensure a successful fast antenna measurement procedure. The techniques with experimental validations are proposed to ensure a reliable field interpolation. Estimations of savings in acquisition time are also provided to show the interest of the proposed method.