Examples of the parametric poloidal field structures applied in this work. Solid lines in the top-left panel show the radial dependences of B_rad/B_pole(r) functions with n_Brad = −2.0 (dark blue), −1.0 (magenta), +0.0 (green), +1.0 (yellow), and +2.0 (cyan). The red-hatched region in the stellar center corresponds to the central convective region, in which the magnetic field is assumed to be constant. The vertical solid red line indicates the stellar surface, where B_rad/B_pole(r) = 1. The remaining plots show the two-dimensional poloidal field structures in the meridional cuts. As in the top-left panel, the red-hatched area shows the central convective region and the solid red curve is the stellar surface.