Microwave spectrum analyzer based on a rapidly tuned spin-torque nano-oscillator

Andrei Slavin

Department of Physics, Oakland University, Rochester, MI 48309, USA

A spintronic method of ultra-fast broadband microwave spectrum analysis is proposed. It uses a rapidly tuned spin torque nano-oscillator (STNO) and does not require injection locking. This method treats an STNO generating a microwave signal as an element with an oscillating resistance. When an external signal is applied to this “resistor” for analysis, it is mixed with the signal generated by the STNO. The resulting mixed voltage contains the “sum” and “difference” frequencies, and the latter produces a DC component when the external frequency matches the frequency generated by the STNO.  The mixed voltage is processed using a low pass filter to exclude the “sum” frequency components and a matched filter to exclude the dependence of the resultant DC voltage on the phase difference between the two signals. It is found analytically and by numerical simulation that the proposed spectrum analyzer has a frequency resolution at a theoretical limit in a real-time scanning bandwidth of 10 GHz and a frequency scanning rate about 20 MHz /ns, while remaining sensitive to signal power as low as the Johnson-Nyquist thermal noise floor.

 Andrei Slavin received PhD degree in Physics in 1977 from the St.Petersburg Technical University, St. Petersburg, Russia.  Dr. Slavin developed a state-of-the-art theory of spin-torque oscillators, which has numerous applications in the theory of current-driven magnetization dynamics in magnetic nanostructures. His current research support includes multiple grants from the U.S. Army, DARPA, SRC and the National Science Foundation. This research involves international collaborations with leading scientists in many countries, including Germany, Ukraine, France, Italy, and the United States. Dr. Slavin is a frequently invited speaker at magnetism conferences around the world.

   Andrei Slavin is Fellow of the American Physical Society, Fellow of the IEEE, and Distinguished Professor  and Chair of the Physics Department at the Oakland University, Rochester, Michigan, USA.