LUMPED DUAL-FREQUENCY IMPEDANCE TRANSFORMERS FOR FREQUENCY-DEPENDENT COMPLEX LOADS

This paper presents lumped dual-frequency impedance transformers for frequency-dependent complex loads. According to different dual-frequency allocations of a complex load in Smith chart, three types of impedance matching networks are presented respectively. Several kinds of lumped circuit blocks are used as basic element for constructing these transformers with design formula deduced. Various examples are given for describing the design procedures.~Good features such as big frequency ratio and big matching bandwidths are demonstrated. These lumped dual-frequency impedance transformers have advantage of much compacter dimensions compared to distributive solutions.