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

TL;DR

This paper presents an integrated piezo-magnonic MEMS device that enables efficient, low-power control of GHz spin-wave signals through magnetoelastic coupling, promising for reconfigurable RF applications.

Contribution

Demonstration of an all-electric, integrated piezo-magnonic MEMS device achieving large phase and amplitude modulation of RF signals with low voltage and power.

Findings

Achieved up to 4π phase modulation at 7 GHz with <20 V drive.

Realized 50 dB amplitude attenuation at 7 GHz with <20 V drive.

Resonant enhancement allows 2π phase swing at 2.2 V with 6 μW power.

Abstract

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 $4\pi$ 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 $2\pi$ 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.