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 $30\,\mathrm{mT}$ 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 $4π$ phase modulation or $\approx 50\,\mathrm{dB}$ amplitude attenuation with drive voltages below $20\,\mathrm{V}$ at $7\,\mathrm{GHz}$. Leveraging the bridge's first bending resonance ($\approx 17\,\mathrm{kHz}$) yields resonant enhancement of the phase modulation efficiency. This allows us to achieve a $2π$ phase swing with just $2.2\,\mathrm{V}$ drive and power consumption of $\approx 6\,μ\mathrm{W}$. Our results highlight piezo-magnonic MEMS as a promising new class of devices for reconfigurable RF front ends and analog signal processors.