An analysis of thin-film resistance networks with two resistive materials

In designing the planar resistor and attenuator using uniform resistive media, if the electrode and structural dimension ratio are extremely small or large, the design is not realizable. In such cases, the realizable design range can be enlarged by using two kinds of resistive media. However, the resistance value can be obtained by solving nonuniform boundary value problems. In this paper, we report an approximate method for evaluating resistances using two kinds of resistive media. Further, the design method for composite thin-film resistance and three-port attenuator is proposed based on the analysis result and conformal mapping. The result of the analysis agrees with the experiment within the practical accuracy.