In the present paper, the effect of gallium β-oxide introduced into the polydimethylsiloxane elastomer on the electrical properties of the composite material is investigated. The dependence of the electrical resistance of the composition on the change in the specific volume electrical conductivity on the content of gallium oxide is established experimentally and the percolation point is determined. The percolation point is 21%, which is slightly higher than the theoretical value calculated by the Monte Carlo method and is 16%. The temperature dependence of the electrical resistance of the composition on the content of the semiconductor filler in the binder is determined. The dielectric characteristics of  the material, such as the tangent of the dielectric loss angle and the permittivity, are studied using the waveguide method on a laboratory stand based on a precision measuring line P1-20. The dielectric characteristics are calculated by changing the displacement of the standing wave nodes in the waveguide when a dielectric is placed in it using the MathCAD program. An experiment to determine the tangent of the dielectric loss angle in the entire X-band from 8 GHz to 12 GHz has shown that the introduction of gallium oxide leads to an increase in the dielectric losses in the composition. Additional dielectric losses in the composition occur with increasing frequency. The dielectric characteristics are significantly degraded when the filler content exceeds 20% (by volume). The influence of the filler on the radio-transparent and radio-absorbing properties of the polymer composition in the centimeter microwave range is studied. The results of the work can be applied in various sectors of the national economy, including radio electronics, microwave technology and medical technology to partially reduce the background of electromagnetic radiation.