Wireless Spintronics Modulation With a Spin Torque Nano-Oscillator (STNO) Array

This letter presents a spin RF-direct modulation using a frequency division multiplex (FDM) with a spin torque nano-oscillator (STNO) array. For the proposed modulation, two STNO are bonded at each branch of a T-junction on a PCB, where a high pass filter (HPF) and a low pass filter (LPF) are connected on each branch of the T-junction to transmit the modulated signal into one antenna. Each STNO modulates by on-off keying (OOK) with digital data directly after setting on the separation of channels for two STNOs into 700 MHz, one STNO at 3.5 GHz frequency and the other at 4.2 GHz, with consideration of the minimum sensitivity and interference related with isolation between channels. A data rate of up to 400 Kbps is obtained at a distance of 10 mm, and the dc power consumption is 3 mW per STNO, including logic circuit operation. The PCB size is as small as 28 × 27 mm, including the 4.2 × 2.1 mm STNO array.