An application of the preference set-based design method to filter designs

Electrical design is usually made with the concepts based on electric circuit theory. Nowadays it needs to consider the electromagnetic (EM) field generated in devices, components, and equipment to achieve their expected performances and satisfy the electromagnetic compatibility (EMC) regulations as well. In such kind of design, EM-field simulators are often used to estimate EM-field effects to circuit performances. In this paper, the application of a multi-objective satisfactory design method to electrical design is discussed. The method, named preference set-based design (PSD), is developed as a concurrent design method in a field of mechanical engineerings. The PSD method is a sort of synthesis technique to optimize multi purposes concurrently. As a first model to electric and electronics fields the method is applied to filter designs and its usefulness is discussed. Applied filter are an ordinary five-order low-pass filter and an electromagnetic interference (EMI) filter composed of plural element parameters and objectives or performances of attenuation characteristics. In practical cases, some unclear parameters should be taken into account, for example a terminal load in some range, and a coupling coefficient in a common-mode chock for EMI filter. Such an uncertainty problem is treated in this study. By using the resultant parameter sets, the attenuation characteristics are analyzed and confirmed whether the performances are satisfied with the required performances.