A closed-form and physics-based compact model is presented for calculating the DC characteristics of Schottky barrier field-effect transistors and dual gated reconfigurable field-effect transistors. The given model calculates the charge-carrier injection over the Schottky barriers. This current is separated into a field emission current, given by charge carriers tunneling through the Schottky barriers and a thermionic emission current, given by charge carriers overcoming the Schottky barriers. The model verification is done by comparing the model results to measurements and TCAD simulations.