In modern defense systems, processing of the electrical power to suitable voltage level and conversion of it to desired operation frequency is a key technology towards achieving high performance, light weight, improved reliability and high efficiency. This is currently achieved through power electronics technology that utilizes power semiconductor switches and passive components for control and processing of electrical power. Due to ever increasing complexity and challenging requirements, majority of defense applications often require power processors to operate with fluctuating source, load, or environment. In all these scenarios, efficiency and power density have to be kept high without compromising the transient response. Furthermore, such switch modulation technique based power converters have to meet the stringent requirements of power quality and electromagnetic compatibility (EMC) military standards. In state-of-the-art (SOA) power converters, fixed gain passive component based filter are used to meet these challenging requirements and satisfy the standards. Such filters are voluminous, very heavy, and cause significant amount of power loss. There has been incremental progress in overcoming these challenges but nothing transformative has been achieved. Progress in multiferroic materials has now brought us closer towards addressing this problem effectively and providing solution that could radically transform the dc-to-dc power conversion systems.
Researchers at Virginia Tech have recently reported large tunable electrical response in functionally graded interfaces. In their work, multilayer thin film graded heterostructures were synthesized on platinized silicon substrate with oxide layers of varying thickness. The graded heterostructure thin films exhibited shift of the hysteresis loops on electric field and polarization axes depending upon the[…]
Researchers at Virginia Tech in collaboration with University of Connecticut have reported a novel approach for achieving high dielectric response over a wide temperature range. In this approach, multilayer ceramic heterostructures with constituent compositions having strategically tuned Curie points (TC) were designed and integrated with varying electrical connectivity. Interestingly, these multilayer structures exhibited different dielectric[…]