Generation of ultra-broadband frequency comb in strongly bistable nonlinear magnonic resonator.

Magnonic frequency combs (MFCs) offer a promising route to compact, energy-efficient platforms for on-chip coherent microwave signal generation and processing. Conventional on-chip comb generation typically relies on nonlinear resonators supporting equidistant, low-loss resonances driven by a monochromatic signal, resulting in fixed comb spacing. Here we introduce and experimentally demonstrate a distinct mechanism for ultra-broadband MFC generation using a highly nonlinear miniaturized magnonic resonator. The small resonator volume, combined with a slow-wave transducer, drives the system deep into the bistable regime where parametric excitation of propagating spin waves facilitates comb formation. Our approach yields over 350 comb lines spanning a 450 MHz bandwidth, with spacing continuously tunable via a two-tone external drive, representing an order-of-magnitude enhancement over prior reports at relatively low power. The platform is ultra-compact, scalable, and highly tunable, establishing a distinct frequency comb paradigm with transformative opportunities in microwave signal processing, neuromorphic computing, and precision sensing.