$\Pi$ -Model Dual-Band Impedance Transformer for Unequal Complex Impedance Loads

This letter presents a π-model dual-band impedance transformer which can match two unequal arbitrary complex loads at two frequencies. The required nonlinear simultaneous equations are derived to obtain the physical parameters of transmission lines and stubs. Return loss for the proposed matching circuit is measured to validate the results of the presented structure simulations. Excellent agreement between analytical and measured results confirms the proposed structure.