A Dual-Frequency Transformer for Complex Impedances With Two Unequal Sections

In this letter, a small dual-frequency transformer with two unequal sections for complex impedances is proposed. To design this transformer, two different groups of nonlinear equations and the corresponding solutions processes are obtained. The results of numerical examples show that two complex impedances can be matched at two different frequencies simultaneously. This proposed transformer can be regarded as the extension of small dual-frequency transformer in two sections for two resistances.