Electrically connected spin-torque oscillators array for 2.4 GHz WiFi band transmission and energy harvesting

Raghav Sharma, Rahul Mishra, Tung Ngo, Yong Xin Guo, Shunsuke Fukami, Hideo Sato, Hideo Ohno, Hyunsoo Yang

Research output: Contribution to journalArticlepeer-review

34 Citations (Scopus)


The mutual synchronization of spin-torque oscillators (STOs) is critical for communication, energy harvesting and neuromorphic applications. Short range magnetic coupling-based synchronization has spatial restrictions (few µm), whereas the long-range electrical synchronization using vortex STOs has limited frequency responses in hundreds MHz (<500 MHz), restricting them for on-chip GHz-range applications. Here, we demonstrate electrical synchronization of four non-vortex uniformly-magnetized STOs using a single common current source in both parallel and series configurations at 2.4 GHz band, resolving the frequency-area quandary for designing STO based on-chip communication systems. Under injection locking, synchronized STOs demonstrate an excellent time-domain stability and substantially improved phase noise performance. By integrating the electrically connected eight STOs, we demonstrate the battery-free energy-harvesting system by utilizing the wireless radio-frequency energy to power electronic devices such as LEDs. Our results highlight the significance of electrical topology (series vs. parallel) while designing an on-chip STOs system.

Original languageEnglish
Article number2924
JournalNature Communications
Issue number1
Publication statusPublished - 2021 Dec 1


Dive into the research topics of 'Electrically connected spin-torque oscillators array for 2.4 GHz WiFi band transmission and energy harvesting'. Together they form a unique fingerprint.

Cite this