Various vibration and noise suppression applications require a high loss factor (tanδ) over a wide frequency range. Homopolymers often do not meet this requirement. However, the damping properties of polymeric composites can be modulated to achieve this goal. In this paper, we devise a simple finite element based unit cell model to calculate the effective tanδ of a composite as a function of frequency. Using this method, we show that if the relaxation times of the constituents are properly chosen, a flat tanδ response over a wide frequency range can be obtained. Inclusions with multiple layers are seen to be particularly suitable towards this end.