Estimation of Material Characteristics of Film-Type Noise Suppressor Using Equivalent Circuit Modeling and Genetic Algorithm

An estimation method of material characteristics of a magnetic film-type noise suppressor on a microstrip line (MSL) was investigated. First, the electrical equivalent circuit of the MSL with a magnetic film was obtained. A resistance due to the ferromagnetic resonance loss was calculated by using the magnetic circuit. A resistance due to the eddy current loss was estimated by the least squares method for regression prediction. Next, the material parameters of the film were estimated by using the genetic algorithm in order to obtain a high noise suppression effect at 5, 7, and 10 GHz and low insertion loss at 1 GHz. The conductive noise suppression effect by the magnetic film with estimated parameters was calculated by using an electromagnetic field simulator. As a result, the noise suppression was maximized around each target frequency, and low insertion loss at 1 GHz was successfully obtained. The results indicate that the proposed estimation method has the potential for material and geometry design of magnetic noise suppressors in order to obtain the required noise suppression effect at the circuit design stage.