In this work, a formula is derived for calculating the total current generated in a tunnel diode under the influence of a microwave field and a magnetic field. In addition, the dependence of the total current of the tunnel diode on the total power induced by the microwave field is theoretically presented and compared with experimental data. For the total current in the tunnel diode, excluding excess current, the current–voltage characteristics were obtained for cases with and without the influence of the microwave field.