An high impedance transformation ratio dual-band matching network with DC isolation capability

A new dual-band impedance matching network for high transformation ratio and with inherent DC isolation capability is presented in this paper. The reported design utilizes two-section transmission line, a coupled-line section, and a stub for dual-band matching between a real- load and source impedances at two arbitrarily chosen frequencies. A closed form design equations aongwith a number of case studies have been provided to demonstrate the effectiveness of the proposed design scheme for very wide range of impedances. Finally, the proposed technique has been validated through a prototype developed on RO4350B for chosen frequencies of f 1 = 1GHz and f 2 = 2GHz. The measured return loss of approx. 20 dB at both the frequencies are in good agreement with the simulation results.