CERAMIC FERRITE BASED MATERIALS FOR THE ABSORPTION OF ELECTROMAGNETICWAVES WITHIN THE FREQUENCY RANGE BETWEEN 100 MHZ AND 12 GHZ

摘要

The submitted invention deals with ceramic ferrite based materials for the absorption of electromagnetic waves within the frequency range between 100 MHz and 12 GHz, measured on toroidal ferritic cores with an external diameter of 7 mm, an internal diameter of 3 mm and a height of 3 mm made from oxides of iron, zinc, nickel, copper, bismuth, cobalt and barium carbonate, characterised by the fact that the contents features the following mole percentages: Fe2O3 = 50 - 90 mol %; NiO = 15 - 50 mol %; ZnO = 0 - 35 mol %; CuO = 0 - 25 mol %; Bi2O3 = 0 - 10 mol %; CoO = 0 - 20 mol %; BaCO3 = 0 - 30 mol %. The final electromagnetic properties are defined by the share of the basic components of oxide materials and the carbonates, the corresponding manufacturing conditions of the ceramic ferrite powder and conditions of high-temperature sintering. The ceramic ferrite materials for the absorption of the electromagnetic waves within the frequency range between 100 MHz and 12 GHz manufactured in different shapes and sizes of ceramic ferrite based products, thin-layer foils and combinations with various organic composites, absorb the electromagnetic waves within the frequency range of the ferromagnetic resonance. The ceramic ferrite based materials represent strategic materials for the application in telecommunication technologies of the new generation for the protection against interference between different telecommunication systems and for the protection of people and residential premises against unwanted and health hazardous electromagnetic waves.