A simplified model of dual-frequency impedance transformers for complex frequency-dependent impedance loads

A simplified model is presented for matching two frequency-dependent complex impedances at two arbitrary frequencies. For the simplest topology form, the proposed impedance transformer consists of only a single transmission line with a shunt stub. The design equations which are the function of the frequency ratio and complex termination impedances are derived analytically. The results of numerical simulations and experiments demonstrate the validity of the proposed transformer.