Frequency Sensing and Detection using Granular Vortex MTJ Nano Oscillator

A new paradigm in sensing and communication is emerging with Radio Frequency Identification (RFID), RF detection, object identification, and sensing capabilities for future Internet of Things (IoT) applications, such as automobiles, logistics, healthcare, and smart living. For sensing and detecting the required frequency, complex, large, and highly energy-consuming circuits based on CMOS technologies are required. Hence, here we propose a granular vortex magnetic tunnel junction nano oscillator for a compact and energy- efficient frequency sensing system. The granularity present in the free layer of magnetic tunnel junction (MTJ) allows the identification of the natural frequency of the magnetic vortex core. Our study presents that as soon as the input frequency matches the natural frequency of the vortex core, the impact of grains on the vortex core is nullified. Otherwise, trapping of the vortex core in different grains produces varying output frequencies. The granular effect and the variation of the aspect ratio of the free layer are examined to determine natural frequency of the vortex core. Further, the frequency sensing and detection mechanism for a specific frequency are demonstrated.