报告人：Prof. Richard W. Ziolkowski教授
主 题：Engineering Passive and Active Metamaterial-inspired Electrically Small Radiating Systems
The introduction of metamaterials and metamaterial-inspired structures into the tool set of RF engineers has led to a wide variety of advances in discovery within the antennas and propagation research areas. The enhanced awareness of complex media, both naturally occurring and artificially constructed, which has been stimulated by the debut of metamaterials, has enabled paradigm shifts in terms of our understanding of how devices and systems operate and our expectations of their performance characteristics. These shifts include the trends of miniaturization, enhanced performance, and multi-functionality of antenna systems for wireless platforms; dispersion engineering to modify the properties, for example, of transmission lines and antennas; scattering mitigation (cloaking, active jamming, perfect absorbers) and enhancements (sensors, detectors); and the tailoring output beams (leaky wave broadside radiators, sub-diffraction limit resolution in remote sensing and highly directive beams for energy transfer and low probability of intercept systems).
A number of advances in the use of metamaterial-inspired constructs to improve the overall efficiency, directivity and bandwidth performance of electrically small antennas (ESAs) in the VHF, UHF and microwave regimes will be reviewed. Several metamaterial-inspired ESA designs have been fabricated and tested; these measurement results are in nice agreement with predictions. While initial efforts emphasized simply high overall efficiencies without using any external matching networks, more recent resonant near-field parasitic (NFRP) designs have also explored the ability to exhibit multi-functional performance, higher directivity and enhanced bandwidths. Multi-functionality is achieved by combining multiple NFRP elements in an electrically small package. Higher directivity from an electrically small system is obtained by combining electric and magnetic NFRP elements to realize Huygens dipole antennas. Enhanced bandwidths are achieved in an electrically small system by augmenting the NFRP antenna internally with non-Foster (active) elements, which are implemented as negative impedance convertor (NIC)-based inductors and capacitors. The development an electrically small system sharing all of these interesting characteristics has been achieved and will be discussed. Connections to similar enhanced radiation and scattering performance characteristics at higher frequencies, such as optical nanoantenna systems, will also be described.
澳大利亚悉尼科技大学全球大数据技术中心杰出教授，美国亚利桑那大学电气与计算机工程学院Litton Industries John M. Leonis Distinguished Professor，光学学院教授。2012年被丹麦技术大学授予荣誉博士学位。美国电子电气工程师协会会士（IEEE Fellow，1994），美国光学学会会士（OSA Fellow，2006）及美国物理学会会士（APS Fellow，2016）。澳大利亚国防科学与技术组织先进科学与技术领域布莱特杰出讲座教授（Australian DSTO Fulbright Distinguished Chair，2014-2015）。IEEE天线与电磁辐射学会主席（2005），仍然活跃在IEEE APS、URSI、OSA及SPIE等各专业学会。