Vias have an option to add via pads. This feature is off by default for new vias but may be turned on in the Via Polygon Properties dialog box. You may open the Via Polygon Properties dialog box by right-clicking on a Via polygon, then selecting Via Properties from the pop-up menu which appears. When this option is on, a via pad is added to the top and bottom of the via which is the same size and shape as the via polygon. The pad is modeled using a planar metal type with loss equivalent to the loss of the via metal being used for the via polygon.