In 1929, Hermann Weyl derived the massless solutions from Dirac equation - relativistic wave for electrons. Neutrinos were thought, decades, to be fermions until discovery of neutrino mass. Moreover, it has been suggested that low energy excitations in condensed matter can Hamiltonian. Recently, photons have also proposed emerge as particles inside photonic crystals. all cases, two linear dispersion bands three-dimensional (3D) momentum space intersect at a single degenerate point point....

We show that the polarization states of electromagnetic waves can be manipulated through reflections by an anisotropic metamaterial plate, and all possible polarizations (circular, elliptic, linear) are realizable via adjusting material parameters. In particular, a linearly polarized light converts its completely to cross direction after reflection under certain conditions. Microwave experiments were performed successfully realize these ideas results in excellent agreement with numerical simulations.

We analyze an S-shaped inclusion for the realization of metamaterials exhibiting left-handed properties. Unlike most conventional inclusions used so far that are composed two separate geometries-typically a split ring and rod-the proposed in this paper is made only one element which yields overlapping negative permittivity permeability response over frequency band about 2.6 GHz. By adopting geometry, we manage to lower down level band, thus allowing occur. Therefore, structure works as stand...

There are many navigation systems for visually impaired people but few can provide dynamic interactions and adaptability to changes. None of these work seamlessly both indoors outdoors. Drishti uses a precise position measurement system, wireless connection, wearable computer, vocal communication interface guide blind users help them travel in familiar unfamiliar environments independently safely. Outdoors, it DGPS as its location system keep the user close possible central line sidewalks...

We demonstrate that by utilizing displacement currents in simple dielectric resonators instead of conduction metallic split-ring and additionally exciting the proper modes, left-handed properties can be observed an array high resonators. Theoretical analysis experimental measurements show as well subwavelength resonance, play important role origin properties. The proposed implementation a metamaterial, based on purely configuration, opens possibility realizing media at terahertz frequencies...

Utilizing microwave continuous-wave Doppler radars to wirelessly detect mechanical vibrations have been attracting more and interests in recent years. In this paper, aiming solve the null point nonlinear issues small-angle approximation-based radar sensors eliminate codomain restriction arctangent demodulation approach, we propose investigate an extended differentiate cross-multiply (DACM) algorithm. With additional accumulator, noise performance of original DACM algorithm is improved....

This paper presents a portable radar system for short-range localization, inverse synthetic aperture imaging, and vital sign tracking. The proposed sensor incorporates frequency-modulated continuous-wave (FMCW) interferometry (Doppler) modes, which enable this to obtain both absolute range information tiny signs (i.e., respiration heartbeat) of human targets. These two different operation modes can be switched through an on-board microcontroller. To simplify the system, utilizes audio card...

By using a phased electromagnetic dipole array to model moving charged particle, we experimentally verified reversed Cherenkov radiation in the left-handed media frequency range from 8.1 9.5 GHz. Our results demonstrate feasibility of new types particle detectors and generators.

A one-dimensional metamaterial is realized using three connected Ω rings printed back-to-back and reversed on two sides of a dielectric substrate. Both transmission prism experiments are reported, yielding concordant results the presence left-handed frequency band. Experiments show reduced losses an enlarged

Narrow bandwidth is a fundamental issue plaguing practical applications of metamaterial absorbers. In this Letter, we show that by deliberately controlling the dispersion and dissipation metamaterial, an ultrawideband perfect absorber with complex-valued constitutive parameters strictly satisfying modified model perfectly matched layer, can be achieved. The nearly power absorption, better than 99%, was experimentally observed in unprecedented 39%, approaching theoretical Rozanov limit. We...

In this paper, we present a fast solution to build Doppler radar system for noncontact vital sign detection (VSD) using instruments that are generally equipped in radio-frequency and communication laboratories. This paper demonstrates the feasibility of conducting research on VSD ordinary The is designed with heterodyne digital quadrature demodulation architecture helps mitigate channel imbalance eliminate complicated dc offset calibration required arctangent demodulation. Moreover, its...

We investigate a general class of electromagnetic devices created with any continuous transformation functions by rigorously calculating the analytical expressions field in whole space. Some interesting phenomena associated these devices, including invisibility cloaks, concentrators, and rotators, are discussed. By carefully choosing function, we can realize which insensitive to perturbations at both inner outer boundaries. Furthermore, find that when coating layer concentrator is realized...

Short-range continuous-wave Doppler radar sensors have been mainly used for noncontact detection of various motions. In this paper, we investigate the feasibility to implement function a remote mouse, an input device computer, by recognizing human gestures based on dual-channel sensor. Direct conversion architecture, symmetric subcarrier modulation, and bandpass sampling techniques are obtain cost-effective solution. An arcsine algorithm motion imaging proposed linearly reconstruct hand...

Noncontact detection of human vital signs based on miniaturized Doppler radar systems (DRSs) can be widely used in healthcare and biomedical applications. Although significant progresses have been achieved, a reliable wireless the presence large-scale random body movements remains technical challenge. In this paper, comprehensive use high-dynamic-range architecture linearized phase demodulation algorithms, we further introduce matched filters to retrieve respiration heartbeat spectra...

A waveguide-based retrieval method for measuring complex permittivity and permeability tensors of metamaterials is presented. In the proposed scheme, multiple independent sets scattering data material under test with different orientations are measured in frequency range corresponding to dominant TE(10) mode. The applied various shows its effectiveness effective parameters extraction.

The Pervasive Computing Laboratory at the University of Florida is dedicated to creating smart environments and assistants enable elderly persons live a longer more independent life home. By achieving this goal, technology will increase chances successful aging despite an ailing health care system (e.g. Medicaid). One essential services required maximize intelligence environment indoor precision tracking system. Such allows home make proactive decisions better serve its occupants by enabling...

Based on electromagnetic wave scattering theory, we demonstrate that magnetic and electric surface currents are induced at the inner boundary of a cylindrical cloak by incoming waves. These have no counterparts in coordinate transform theory. In addition, fields can penetrate into concealed region under specified conditions, but carry power. The field distribution be unsymmetrical when circularly polarized is obliquely incident onto cloak. far-field for nonideal also theoretically addressed.

In this paper, analyses on sensitivity and link budget have been presented to guide the design of high-sensitivity noncontact vital sign detector. Important issues such as flicker noise, baseband bandwidth, gain discussed with practical considerations analog-to-digital interface signal processing methods in detection. Based analyses, a direct-conversion 5.8-GHz radar sensor chip 1-GHz bandwidth was designed fabricated. This is software configurable set operation point detection range for...

The electromagnetic characteristics of plane-transformed invisibility cloaks are quantitatively studied in this paper.We take elliptical cylindrical cloak as the example, and use an wave expansion method to obtain scattered field.It is demonstrated that ideal inherently visible.Noticeable field scattering penetration will be induced when exposed directly wave.However, long consists a perfect electric conducting lining at interior surface, can still achieved along direction parallel major...

Electromagnetic materials lacking local time-reversal symmetry, such as gyrotropic materials, are of keen interest and importance both scientifically technologically. Scientifically, topologically nontrivial phenomena, photonic chiral edge states, allow for reflection-free transport even in the presence large disorder. Technologically, nonreciprocal devices, optical isolators circulators, play critical roles communication computing technologies because their ability to eliminate cross-talk...

Miniaturized Doppler radar sensor (DRS) for noncontact motion detection is a hot topic in the microwave community. Previously, small-scale physiological signals such as human respiration and heartbeat rates are primary interest of study. In this paper, we propose comprehensive approach that can be used to improve demodulation linearity DRSs, detailed time-domain information ranging from micro-scale large scale accurately reconstructed. Experiments show based on digital-IF receiver...

This paper presents an experimental investigation that demonstrates the possibility of 1-D imaging human cardiac motion using a microwave Doppler sensor. Compared with previous works primarily monitored respiration and heartbeat rates, reconstruction in this work will provide more information for time-domain clinical diagnosis. To fully recover from backscattered signal, instrument-based digital-IF radar sensor employing dc-offset removal extended differentiate cross-multiply algorithm was...

In this paper, we experimentally realized a steering antenna using type of active metamaterial with tunable refractive index. The is by periodically printed subwavelength metallic resonant patterns embedded microwave varactors. effective index can be controlled low direct-current (dc) bias voltage applied to the In-phase electromagnetic waves transmitting in different zones such slab experience phase delays, and, consequently, output direction transmitted wave steered progressive shift along...

This paper presents a printed circuit board realization of K-band portable frequency-modulated continuous-wave radar transceiver with beamforming array for short-range localization. The transmitter channel the proposed consists free-running voltage-controlled oscillator (VCO) and single patch antenna. A linear chirp signal is generated by VCO, which controlled an analog "sawtooth" voltage generator. receiver has four-element array, six-port circuit, baseband circuit. beam can be continuously...