Compact Tunable Microwave Filters Driven by the Spin–Orbit Torque

Tunable microwave devices are essential for modern communication systems, where compactness, high integration, and low power consumption are crucial. Meanwhile, spin–orbit torque (SOT)‐driven magnetization switching has been widely utilized in magnetic random access memory and spintronic logic devices, capitalizing on its low power consumption and scalability. However, the utilization of intrinsic advantages in spintronic devices for practical tunable microwave applications remains underdeveloped. Current tunable microwave devices often face limitations such as large device footprints, high power consumption, and insufficient tuning ranges. Here, the design and realization of a miniaturized, highly integrated tunable filter based on a Pt/CoFeB bilayer structure are reported. The Larmor precession frequency in the ferromagnetic CoFeB layer is modulated by the SOT and further achieves the tuning of microwave frequency up to about 0.5 GHz. A phenomenological model is proposed to describe the modulation of resonance frequency by the SOT. Meanwhile, the influence of SOT on the ferromagnetic resonance has been illustrated in detail through micromagnetic simulations. The study demonstrates the potential of SOT on the application of tunable microwave filters, further offering a promising route for the development of next‐generation compact and energy‐efficient microwave components.