Non-Lumped Microwave Topolectrical Resonator Based on the Su-Schrieffer-Heeger Model

Topological states realized in metamaterials have provided a versatile platform for exploring topological physics and enabling novel applications, with topolectrical circuits emerging as a prominent example. However, previous research in this field has primarily focused on lumped-element implementations, while non-lumped microwave circuits remain relatively underexplored. In this work, we design and investigate a one-dimensional non-lumped Su-Schrieffer-Heeger (SSH) topolectrical circuit composed of copper parallel-plate transmission lines and inductors, offering compatibility with integrated microwave applications. Full-wave microwave simulations in the 0-10 GHz range show excellent agreement with theoretical predictions. The impedance spectrum of a five-unit-cell system displays periodic resonant passbands and stopbands corresponding to bulk states, while distinct high-Q (on the order of 10²) topological boundary resonances (TBRs) emerge within the stopbands, indicating the presence of localized edge states. Furthermore, the TBRs vanish when the system is reconfigured into the trivial phase, providing direct evidence of its topological nature. These response characteristics make the proposed resonator a promising candidate for future microwave devices and topological circuit applications.