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Hybrid MnZn/NiZn/PVC polymer composite materials have been prepared using a dry low-temperature hot-pressing process and the influence of particle size, concentration, and the fraction ratio of the dual MnZn/NiZn ferrite filler on their complex permeability Â¿ = Â¿'-j Â¿" and electromagnetic wave (EM-wave) absorbing properties were investigated within the frequency range of 1-3000 MHz. The observed frequency dispersion of permeability was of a relaxation type and caused by a resonance of vibrating domain walls and a natural ferromagnetic resonance of precessing magnetic moments in domains. The complex permeability and resonance frequency f res of hybrid composites have been affected mainly by changes in concentration and fraction ratio of ferrite filler: the Â¿' at low frequency decreased and f res shifted towards the higher frequency region with the decrease of ferrite concentration and with the configuration change from the MnZn/PVC composite to NiZn/PVC one. Measured values of complex permeability were used to determine the return loss RL using a model of a single-layered EM-wave absorber backed by a perfect conductor. In the designed single layer absorbers, the RL as well as the matching frequency f m, matching thickness d m, bandwidth Â¿f for RL Â¿ -20 dB, and the minimum of return loss (RL)min seem to be strongly dependent on particle size, concentration, and the fraction ratio of the dual MnZn/NiZn ferrite filler.