The geometrical theory of diffraction has been applied to analysis of the backscattered fields of a cube in the plane normal to four edges of the cube. The results of this diffraction analysis are used to calculate the backscattered fields at harmonically related frequencies, which are then combined with experimental data and transformed to obtain impulse, step, and ramp responses in the time domain. The inclusion of the calculated high‐frequency data results in a more precise determination of the time‐response waveforms than is possible with only low‐frequency measured data. As an example of the results, the impulse, step, and ramp responses for vertical and horizontal polarization are presented for θ = 0° (specular directio