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The functionality of a traditional photonic device is usually realized by reshaping the wavefront of the light that relies on gradual phase changes along the optical paths, which are accomplished by either controlling the surface topography or varying the spatial profile of the refractive index. The thickness of photonic devices usually remains comparable to the wavelength of the light. However, further...
There has been persistent exploration of new active materials and novel device architectures to dynamically control light with larger modulation depth and increased spectral range, at faster speed, and using less power. In this presentation, I will present experimental results showing that samarium nickelate (SmNiO3), a prototypical phase-change perovskite nickelate, exhibits reversible large refractive...
Metasurface, an optically thin layer of metarmaterials (MTMs), has recently attracted great interest for its capability to manipulate the phase of a propagating wave [1–3]. Such a surface approach of metamaterials has paved a way to escape from the difficulties in fabricating three-dimension (3D) metamaterials. Recently, optically thin metasurface has been demonstrated to achieve invisibility carpet...
The volume integral equation (VIE) formulations have been very accurate and efficient methods in modeling of inhomogeneous objects in electromagnetic areas. Over the years, various volume integral equation formations have been developed. In these formulations, the dielectric object is discretized into small sub-domains, such as tetrahedrons. Then basis functions are defined in each sub-domain and...
We introduce composite two-dimensional optical lattices representing a superposition of two mutually rotated square patterns and allowing observation of continuous transformation between aperiodic and completely periodic optical lattices upon variation of the rotation angle θ. A remarkable property of this lattice is that it acquires periodicity only for specific rotation angles cos θ = b/c, sin θ...
Photonic crystal (PhC) nanobeam cavities have attracted increasing attention owing to the advantages of high Q-factor, small mode volume and no limitation of FSR. Various PhC cavities have been developed for optical communications, optical sensors, optomechanics, etc.. We investigate the design, fabrication, and experimental characterization of high quality factor PhCnanobeam cavities on silicon....
Introduction: In the past decades, fiber-to-the-home access networks, chip-to-chip interconnects, and on-chip optical interconnects have gain widespread interest owing to the inherent advantages of large bandwidth, high signal noise ratio, small size and low power consumption. Because of the compatibility with existing complementary metal-oxide-semiconductor (CMOS) technology, Si photonics became...
With the development of VLBI technology, the correlator system of observation station is constantly upgrading, so as to adapt to new data format and higher processing speed. Now the conversion of data format from Mark 5B to VDIF has been built by the researchers around the world. Once completed, it will be conducive to VLBI international collaboration. Hence it is very meaningful to study the VDIF...
In actual applications of inverse synthetic aperture radar (ISAR), continuous data collection may be unachievable or the collection data during some periods are missing in long coherent processing interval, so it is often difficult to obtain a well-focused image. CS based ISAR imaging yields a good performance in high SNR. However, the performance of CS based method degrades with the increase of the...
In this paper, PO solution of electromagnetic scattering of anisotropic coating target under point source excitation has been derived. Firstly, According to the tangent plane approximation in the PO field, the high frequency scattering problems of point source excitation infinite plane model coated anisotropic medium can be solved specifically. Secondly, we can expand any scattering wave field including...
On basis of the principle electromagnetic induction, the connections about initial firing rate of projectile and turns, sectional area and electric current of the coil have been deduced, and then a kind of four stage reluctance electromagnetic launcher is designed. In order to exert pulse current on the coil properly, a photoelectric sensor is installed into coil track. Therefore, the projectile can...
Compared with conventional drying technology, microwave assisted drying technology has some remarkable properties, such as material-selective, instantaneous and volumetric heating, which leads to extremely broad applications in materials drying. The efficiency of microwave drying is found to be dependent on various factors, such as temperature, moisture content, the dimension of material and so on...
This paper discussed a control system for an HPMSM machine with a stator based field coil aiming at maximum efficiency of the inverter-machine system. A new procedure for efficiency-optimal inverter-machine propulsion system has been introduced. An iterative process for optimal current distribution is described with multidimensional tables of overall losses and efficiencies. Due to high-speed calculations,...
As the development of people's pursuit for driving experience, atmosphere lamp is increasingly used in automobile interior lighting. How to accurately control and change the color of atmosphere light becomes an urgent problem. In addition, any electronic system applying in automobile must go through strict ESD test to make sure that system can work stably in the real environment. In this paper, a...
One of the prominent techniques used to mitigate the electromagnetic energy radiation (which causes interference in the signal transmission) is smart antenna. The smart antenna system remains the noticeable dynamic approach employed to develop the power output of the signal of interest in a specified direction and reduce the interfering signal power in unnecessary direction. Smart antenna system comprises...
Over the air testing of multiple antenna systems has attracted great attention in recent years. The research and standardization work have been focused on evaluating user equipment (UE) in two dimension (2D) radio propagation channel models. This paper proposes two future direction of over the air testing: 1) performance evaluation of WiFi devices under realistic propagation scenarios and 2) 3D radio...
Limited factors and calculation method of VOLTE capacity were analyzed in this paper. Firstly, several factors of the limited capacity were presented. Then, the influence of key technology was analyzed. At last, the calculation methods of each kind of restriction factors were analyzed and examples of calculation were proposed.
Ultra wideband pulsed ground penetrating radar (GPR) detects buried object or underground medium characteristic by emitting and receiving pulsed electromagnetic waves. Establishing underground medium equivalent model and studying the electromagnetic wave propagation characteristic in media are very important to GPR data processing and underground object detecting. This paper introduces the actual...
Bioradar is an emerging concept to aim at human targets detection. Since the vital signs are weak, surrounding environment has greater interference on it. It is difficult to obtain the high performance of static human body detection and localization. Dual-channel SFCW radar is used to improve this problem and a new method of static human body detection based on dual-channel SFCW radar is proposed...
In our previous publication, we have designed a ground penetrating radar (GPR) system with and antenna array for in-situ estimation of the thickness and dielectric permittivity of the asphalt pavement. In this paper, we change the work mode of the GPR antenna array from the ground-coupled mode to the off-ground one, accelerating the data acquisition speed required for highway inspection. The GPR antenna...
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