Demarets, MaelMaelDemaretsAnanthapadmanabha Rao, VadirajVadirajAnanthapadmanabha RaoCaloz, C.C.CalozDe Greve, KristiaanKristiaanDe Greve2026-09-222026-09-2220262331-7019https://imec-publications.be/handle/20.500.12860/60459Isolators are commonly found in the amplification chain of microwave setups to shield sensitive devices such as superconducting qubits from noise and back-scattered signals. Conventional ferrite-based isolators are bulky, lossy, and rely on strong magnetic fields, which pose challenges for their co-integration in large-scale superconducting devices. Although several magnetless approaches based on parametric modulation have been explored to overcome these limitations, none has yet experimentally demonstrated wideband isolation on a par with ferrite devices. Here, we propose a compact modulation-based isolator that achieves large isolation bandwidth using a dispersion-engineered transmission line. The engineered line forms an effective two-mode system that enables broadband isolation by supporting adiabatic mode conversion over a wide instantaneous bandwidth. Numerical simulations show that this architecture can provide more than 20-dB isolation across 4–8 GHz, matching the performance of ferrite-based isolators. Moreover, we propose an on-chip superconducting device implementation that shows promise against parameter variations and enables a scalable path for co-integration with future large-scale superconducting systems.engJournal article10.1103/vjy5-wxpyWOS:001842563600004