Designing Harmonic Transponders Using Lumped-Component Matching Circuits

Design of harmonic transponders is presented in a case when the harmonic operating frequencies are implemented with a separate matching circuit based on lumped components. The required frequency multiplication is generated by a diode, and both varactor and detector diodes are investigated. Benefits and drawbacks of the proposed design compared to completely self-resonant transponder antennas are considered. Transponders are designed for three different diodes. Based on the obtained results, it can be seen that when using a matching-circuit-based transponder, antenna design is more straightforward. The main design challenge in this approach becomes finding a suitably well-performing matching circuit and circuit topology.