An electromagnetic wave emitter makes an obliquely incident from the air on the surface of a liquid with refractive index n 2 a linearly polarized uniform plane wave with average power density = 12 mW/m2 and frequency f = 7.2 GHz. For the analysis, a system is considered of coordinates P av (20, ), TT 7t 4' = such that the liquid occupies the half-space z 0), H (z > 0); h) The electric fields associated with the reflected and transmitted waves, respectively , (z > 0), E, (z < 0).