Magneto-electric nano-composite for analog tunable radio frequency filters

Abstract

The emerging field of magnetoelectric electronics opens significant opportunities for the next generation of sensors and wireless devices. A key feature of magneto-electric materials is the coupling between their magnetic and electronic properties that enables a voltage to be induced by a magnetic field, or a magnetic response to be induced by an electric field. This occurs in ferroelectric and ferromagnetic bi-layers. It also intrinsically occurs in multiferroics but obtaining a large room temperature magneto-electric effect with such materials can be challenging.

The National Isotope Centre, part of the Institute of Geological and Nuclear Sciences (GNS Science), has been working with Victoria University of Wellington (VUW) on a novel idea to use low energy ion implantation to create ferromagnetic nanoparticles on ferroelectric and multiferroic thin films to create a magneto-electric nanoparticle composite thin film. They demonstrated the viability of magneto-electric nano-composites in two early stage proofs-ofconcept: a tunable radio frequency filter for wireless systems and a zero-power magnetometer measuring small electrical signals. The aim of this project is to assess the range of fields that this composite could have applications in, identifying the most promising of those fields and assessing the most promising applications in that field. Furthermore, this project also seeks out potential partners in New Zealand and a business case was subsequently prepared, which will be used to apply for government funding to pursue research on the technology, and to begin its commercialisation.

In this study nine fields were found to potentially benefit from the use of this technology. They were analysed and compared, using preliminary market validation, resulting in the decision to investigate further the tunable radio frequency (RF) filter market, which is projected at US$13 billion by 2020. RF filters are designed using an original method patented in the 1930s allowing a filter to address only one frequency. As a result, a device must integrate as many filters as frequencies it needs to use, which could be more than 50 for a recent smartphone. A tunable RF filter with a 20% tunability could disrupt this market by providing a huge gain of space, weight, and power efficiency. The RF market is also promising because of the wireless trend, which is occurring all over the world where everything is progressively connected to the what is called the ‘Internet of Things’ – the most important market for the next generation of interconnected electronics. During a year of literature review, interviews and participation at international fairs, the research team has built a value proposition case, a technology review, a market and competitive analysis, an intellectual property assessment and a commercialisation pathway, which are detailed in this project report.

The initial Smart Idea funding from the government has now ended and, if the project is to be kept alive, it needs to produce a quick-to-market application to unlock new credits. This report proposes a structured roadmap for several applications, starting with a tunable RF filter prototype for underwater communication. This has been progressed by GNS Science, embarking on a grant application during this writing. If granted, this funding could open the way to make New Zealand a champion in tunable RF filters and a research and development (R&D) hub for next generation nano-electronics.