Monolithic piezo-magnonic-MEMS for efficient modulation of RF signals

Compact, low-power analog RF components are essential for next-generation microwave electronics and wireless systems. We demonstrate an all-electric integrated piezo-magnonic microelectromechanical system that enables efficient voltage control of GHz spin-wave signals via magnetoelastic coupling. Exploiting the large strain in a CoFeB magnonic waveguide integrated on a silicon bridge with piezoelectric actuation, very large values of the magnetoelectric field (up to $30\mathrm{m}\mathrm{T}$ at $30\mathrm{V}$) are obtained, thus achieving reversible phase and amplitude control of propagating spin waves. In the static regime, we achieve either up to $4\pi$ phase modulation or $\approx 50\mathrm{d}\mathrm{B}$ amplitude attenuation with drive voltages below $20\mathrm{V}$ at $7\mathrm{G}\mathrm{H}\mathrm{z}$. Leveraging the bridge’s first bending resonance ($\approx 17\mathrm{k}\mathrm{H}\mathrm{z}$) yields resonant enhancement of the phase modulation efficiency. This allows us to achieve a $2\pi$ phase swing with just $2.2\mathrm{V}$ drive and power consumption of $\approx 6\mu \mathrm{W}$. Our results highlight piezo-magnonic MEMS as a promising new class of devices for reconfigurable RF front ends and analog signal processors.