SpecEES: Chip-Scale Millimeter-Wave Spectrum / Signal Analyzer Using Spin-Wave Diffraction and Interference

University Of Notre Dame, Notre Dame IN

Investigators

Abstract

The dramatic growth in wideband cellular networks, the proliferation of public and private WiFi access points, and the impending demand of machine-to-machine (M2M) and Internet-of-Things (IoT) devices put a premium on the efficient use of the available electromagnetic spectrum. Current regulation regarding usage of the electromagnetic spectrum follows a static licensed allocation model. However, it is widely recognized that this model is no longer able to meet the rapidly growing demands for spectrum access. Dynamic spectrum access and cognitive radios have been proposed as solutions to the problem, but their ultimate success is predicated upon the existence of high-quality spectrum occupancy data. This project proposes a bold new concept for dynamic spectrum data analysis, which will significantly improve the efficiency of radio spectrum utilization while at the same time providing improved energy efficiency. Specifically, this concept is based on a fundamentally new way of processing millimeter-wave and microwave information using spin waves in magnetic thin films. Such new technology will make possible the replacement of today's bulky passive electromagnetic systems by a chip-scale, low-power device. If successful, the devices proposed in this project will become a new class of millimeter-wave and microwave components, performing many functions that today are only achievable with transistor-based circuits. Students will be educated and trained in this new technology. Graduate students will be exposed to avenues for commercialization through University of Notre Dame's Innovation Park and the Engineering Science and Technology Entrepreneurship Excellence Masters (ESTEEM) Program that partners science, engineering, and business students with research faculty toward the goal of commercializing locally-generated fundamental research. Local high-school teachers will participate through an NSF Research Experiences for Teachers (RET) program, which will also include faculty from the local Ivy Tech Community College. This proposal presents a micromagnetics-based real-time spectrum sensor that is low-cost, high-performance, and chip-scale. The combination of these features means this sensor can be deployed on individual devices in a network or IoT devices to provide the high spatial resolution necessary to realize spatial dynamic spectrum access and to provide the speed and resolution necessary to realize temporal dynamic spectrum access. In the proposed scheme, millimeter-wave and microwave signals are converted to spin-waves and processed by spin-wave interference, and then the intensity distribution of the interference patterns is converted back to the electrical domain. In particular, a spin-wave-based frequency spectrum and signal analyzer device is proposed that can perform high-resolution, real-time, wideband spectral analysis on millimeter-wave and microwave signals and provide an on-chip, low-power compact replacement for bulky and expensive spectrum analyzer instruments, which contain a large assembly of discrete microwave components (filters, sweep-oscillators, etc.). The benefits of this scheme, which combine small size, low power, and high speed, derive from the low-power and short-wavelength characteristics of spin waves. As such, our approach provides a potential solution to a particularly challenging task in modern electronics, namely to realize devices that are both fast and low-power. In conventional CMOS-based electronics, power consumption increases quickly with increasing computing speed (clock rate), which makes it very challenging (maybe impossible) to simultaneously achieve low power and high speed (several tens of gigahertz) operation in electrical devices. Our proposed spin-wave-based devices may provide a solution to this fundamental problem.