Spin nano–oscillator–based wireless communication

Abstract

Spin–torque nano–oscillators (STNOs) have outstanding advantages of a high degree of compactness, high–frequency tunability, and good compatibility with the standard complementary metal–oxide–semiconductor process, which offer prospects for future wireless communication. There have as yet been no reports on wireless communication using STNOs, since the STNOs also have notable disadvantages such as lower output power and poorer spectral purity in comparison with those of LC voltage–controlled oscillators. Here we show that wireless communication is achieved by a proper choice of modulation scheme despite these drawbacks of STNOs. By adopting direct binary amplitude shift keying modulation and non–coherent demodulation, we demonstrate STNO–based wireless communication with 200–kbps data rate at a distance of 1 m between transmitter and receiver. It is shown, from the analysis of STNO noise, that the maximum data rate can be extended up to 1.48 Gbps with 1–ns turn–on time. For the fabricated STNO, the maximum data rate is 5 Mbps which is limited by the rise time measured in the total system. The result will provide a viable route to real microwave application of STNOs.

Spin-Torque and Spin-Hall Nano-Oscillators

“…3) Noncoherent transceiver: Taking advantage of the fast switching speed of STNOs, an STNO-based wireless communication system with binary amplitude shift keying (ASK) has been demonstrated in [228]. In this system, the STNO performs the ASK modulation at the transmitter and a simple envelope detector recovers the data at the receiver.…”

Oscillation characteristics of zero-field spin transfer oscillators with field-like torque

“…The STOs have high frequency microwave, large tuning range via applied field or current, 13 high modulation rates, 14 small footprints, and the same compatibility with the standard complementary metal-oxide-semiconductor process. Thus, it can be used as the frequency-tunable transmitters and receivers for wireless communication purposes, 15 nanoscale dynamic magnetic field sensors 16 and recording heads of high-density hard disk drives. 17,18 However, the necessity of an applied magnetic field has severally limited the STOs' potential applications in microwave generation and other fields.…”

Integration of GMR-based spin torque oscillators and CMOS circuitry

“…Nevertheless, these immature STOs have currently two main issues, the limited output power and considerable phase noise, which make them less competitive than CMOS oscillators for some applications. Despite these limitations, STOs have already shown great potential to be used as modulators in non-coherent high-speed wireless communication systems utilizing amplitude-shift keying modulation [12], where phase noise is no longer an issue. Currently, extensive research is taking place to further understand and improve the linewidth (phase noise) [13,14], increase the output power [2,7], and reduce or even remove the bias field [15,16].…”