Metamaterial-inspired configurations to enhance the directivity of electrically small antennas

© 2016 European Association of Antennas and Propagation. It has been demonstrated that metamaterial-inspired electrically small antennas (ESAs) can be designed to have high radiation efficiencies and even large bandwidths with non-Foster circuit augmentations. However, being electrically small, it still remains a challenge to obtain directivities over interesting bandwidths which exceed those of simple dipoles, especially with only passive constructs. Different classes of metamaterial-inspired ESAs that have successfully produced higher directivities will be reviewed and new configurations will be introduced and discussed

Passive and active metamaterial-inspired nano-scale antennas

© 2016 European Association of Antennas and Propagation. A variety of open and closed multi-layered nanoparticle structures have been considered analytically and numerically for their use as scatterers and radiators. These include metamaterial-inspired structures based on dielectrics and metals excited by either plane waves or electric Hertzian dipoles at optical frequencies. Both passive and active (gain impregnated dielectric) materials have been considered. Enhanced and mitigated scattering and radiating effects have been modeled. Nano-antenna and nano-amplifier configurations for optical applications have been emphasized. A review of these modeling efforts will be presented

Generating localized waves from independently addressable pulse driven arrays

© 2016 IEEE. After a brief historical perspective on the origins and developments of space-time coupled solutions of the wave equation, the so-called localized waves (LWs), my presentation will emphasize how they can be and have been launched from independently addressable pulse driven (IAPD) arrays. These IAPD arrays are characterized by each element having the possibility to be driven with an individualized time domain waveform. Several acoustic and electromagnetic LW solutions, the IAPD arrays than can launch them, and the near-field and extended far-field region behaviors characterizing the localized beams launched by them, as well as the experiments that have verified these effects, will be discussed

Metamaterials: The early years in the USA

© R.W. Ziolkowski, Published by EDP Sciences, 2014 Metamaterials are artificial materials formed by embedding highly subwavelength inclusions in a host medium, which yield homogenized permittivity and permeability values. By design they offer the promise of exotic physics responses not generally available with naturally occurring materials, as well as the ability to tailor their properties to specific applications. The initial years of discovery emphasized confirming many of their exotic properties and exploring their actual potential for science and engineering applications. These seed efforts have born the sweet fruit enjoyed by the current generation of metamaterials scientists and engineers. This review will emphasize the initial investigative forays in the USA that supported and encouraged the development of the metamaterials era and the subsequent recognition that they do have significant advantages for practical applications

1987 IEEE AP distinguished achievement awardee, Prof. Georges A. Deschamps, a true gentleman and distinguished scholar

© 2017 IEEE. Prof. Georges Armand Deschamps was a distinguished scholar, inventor, advisor, and mentor. As a Senior Engineer with the Federal Telecommunications Laboratory and then the Head of the Antenna Laboratory at the University of Illinois at Urbana-Champaign, he championed many pioneering efforts including microstrip antennas, frequency independent antennas, ray techniques, and the use of advanced mathematical methods in electromagnetics, such as quaternions, hyperbolic geometries, and differential forms, to solve many practical and important engineering problems

Metamaterial-inspired Electrically Small Platforms: Enhanced Directivity Properties

© 2018 IEEE. A variety of near-field resonant parasitic (NFRP) antennas have been developed as electrically small platforms to realize high directivity. These include compact arrays and Huygens dipole and multipole radiating systems. A brief review of these developments and their scattering equivalents will be presented

Metamaterial-inspired solution to lackluster on-chip antenna performance

© 2019 IEEE. An electric or magnetic dipole antenna located on the interface between a low and high permittivity dielectric faces the problem that the physics tells us that the majority of the power it emits will be radiated into the high dielectric region. This effect is a significant problem for an on-chip antenna associated with systems-on-chip applications such as mobile computing and embedded systems. It is demonstrated that one can use metamaterial-inspired Huygens antennas to overcome this very practical problem

Low profile, broadside radiating, electrically small huygens source antennas

© 2015 IEEE. It is demonstrated numerically that a metamaterial-inspired, low profile (height approximately A/80), electrically small (ka = 0.45) Huygens source antenna can be designed to radiate at 300 MHz in its broadside direction with a high radiation efficiency and a large front-to-back ratio. Two electrically small, near-field resonant parasitic (NFRP) antennas are first designed. Both are based on a coax-fed dipole antenna. An electric dipole response is obtained by combining it with a tunable Egyptian axe dipole (EAD) NFRP element. A magnetic dipole response is obtained by spatially loading the driven dipole with tunable, extruded capacitively loaded loop (CLL) NFRP elements. The driven dipole and the EAD and CLL NFRP elements are combined together and retuned to achieve a broadside radiating Huygens source antenna. Two different designs, one with two CLL elements and one with four, are obtained, and their performance characteristics are compared

Design and measurements of an electrically small, broad bandwidth, non-Foster circuit-augmented protractor antenna

A broad bandwidth, electrically small, metamaterial-inspired protractor antenna was designed, fabricated and tested around 300 MHz. Its broad bandwidth property was achieved by augmenting the protractor-shaped near-field resonant parasitic (NFRP) element with a non-Foster circuit. The resulting active NFRP element provided the means to surpass the fundamental passive limits. The measurement results for this non-Foster protractor antenna showed more than a 10 times increase of the 10 dB fractional bandwidth (FBW 10dB) of the original passive version. The corresponding half-power bandwidth (BW 3dB) was more than 8.24 times the passive upper bound. © 2012 American Institute of Physics

Electrically small metamaterial-inspired antennas with active near field resonant parasitic elements: From theory to practice

© 2017 Euraap. By augmenting several classes of metamaterial-inspired near-field resonant parasitic (NFRP) electrically small antennas (ESAs) with active (non-Foster) circuits, we have achieved performance characteristics surpassing their fundamental passive bounds. The designs not only have high radiation efficiencies, but they also exhibit large frequency bandwidths, large beam widths, large front-to-back ratios, and high directivities. Furthermore, the various initially theoretical and simulated designs have led to practical realizations. These active NFRP ESAs will be reviewed and recently reported designs will be introduced and discussed