scholarly journals Investigation and Study of Mode Splitting in Near Field Inductive Communication Systems

2013 ◽  
Vol 59 (2) ◽  
pp. 185-194 ◽  
Author(s):  
Hoa Doan Thanh ◽  
Johnson I. Agbinya
Keyword(s):  
Communication Systems ◽  
Power Efficiency ◽  
Transfer Functions ◽  
Near Field ◽  
Coupling Coefficients ◽  
Mode Splitting ◽  
Natural Response ◽  
Investigation And Study ◽  
Degree Of Coupling ◽  
Inductive Communication

Abstract Frequency splitting is a near field inductive communication phenomenon where the resonant frequency divides into many separate frequencies or to different modes. In this paper, we show that this phenomenon depends on the coupling coefficients or the natural response of the circuit by using the circuit theory to derive these splitting frequencies. Also, the rules for the general matrix that is used to solve for splitting frequencies are also demonstrated clearly. Mode splitting is observed for peer-to-peer, three coils and four coil systems due to the existence of the nearest and second neighbour interactions. In particular, two, three and four modes have been analysed for two, three, and four coil systems respectively. However, the number of modes for these systems can be changed according to the degree of coupling. The differences in the resultant splitting frequencies with and without the second neighbour interaction are shown in the simulation results. Furthermore, we assess the system performances regarding to power efficiency through the inductive transfer functions. Besides, either coupling coefficients at resonance or the simplified transfer functions in some specific scenarios can be obtained by having an insight into these transfer functions. Finally, we recognise and propose that splitting frequency phenomenon can be deployed to transmit signals at many frequencies concurrently.

scholarly journals Magnetic Positioning Technique Integrated with Near-Field Communication for Wireless EV Charging

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1081 ◽  
Author(s):  
Zhongnan Qian ◽  
Rui Yan ◽  
Zeqian Cheng ◽  
Jiande Wu ◽  
Xiangning He
Keyword(s):  
Relative Position ◽  
Data Transmission ◽  
Power Efficiency ◽  
Near Field ◽  
Three Dimensional ◽  
Secondary Coil ◽  
Power Transfer ◽  
Electric Vehicle Charging ◽  
Position Detection ◽  
Positioning Method

For wireless electric vehicle charging, the relative position of the primary and secondary coils has significant impacts on the transferred power, efficiency and leakage magnetic flux. In this paper, a magnetic positioning method using simultaneous power and data transmission (SWPDT) is proposed for power coil alignment. Four signal coils are installed on the primary coil to detect the secondary coil position. By measuring the positioning signal amplitudes from the four signal coils, the power coil relative position can be obtained. Moreover, all the communication needed in the positioning process can be satisfied well by SWPDT technology, and no extra radio frequency (RF) communication hardware is needed. The proposed positioning method can work properly both in power transfer online condition and in power transfer offline condition. Thus, a highly integrated wireless charging system is achieved, which features simultaneous power transfer, data transmission and position detection. A positioning experimental setup is built to verify the proposed method. The experimental results demonstrate that the positioning resolution can be maintained no lower than 1 cm in a 1060 mm × 900 mm elliptical region for a pair of 510 mm × 410 mm rectangular power coils. The three-dimensional positioning accuracy achieves up to 1 cm.

scholarly journals Vortex Polymer Optical Fiber with 64 Stable OAM States

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2776
Author(s):  
José A. Borda-Hernández ◽  
Claudia M. Serpa-Imbett ◽  
Hugo E. Hernandez Figueroa
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Communication Systems ◽  
Low Cost ◽  
Higher Order ◽  
Coupling Coefficients ◽  
Polymer Optical Fiber ◽  
Optical Polymer ◽  
Polymer Optical Fibers ◽  
Low Dispersion

This research introduces a numerical design of an air-core vortex polymer optical fiber in cyclic transparent optical polymer (CYTOP) that propagates 32 orbital angular momentum (OAM) modes, i.e., it may support up to 64 stable OAM-states considering left- and right-handed circular polarizations. This fiber seeks to be an alternative to increase the capacity of short-range optical communication systems multiplexed by modes, in agreement with the high demand of low-cost, insensitive-to-bending and easy-to-handle fibers similar to others optical fibers fabricated in polymers. This novel fiber possesses unique characteristics: a diameter of 50 µm that would allow a high mechanical compatibility with commercially available polymer optical fibers, a difference of effective index between neighbor OAM modes of around 10−4 over a bandwidth from 1 to 1.6 µm, propagation losses of approximately 15 × 10−3 dB/m for all OAM modes, and a very low dispersion for OAM higher order modes (±l = 16) of up to +2.5 ps/km-nm compared with OAM lower order modes at a telecom wavelength of 1.3 µm, in which the CYTOP exhibits a minimal attenuation. The spectra of mutual coupling coefficients between modes are computed considering small bends of up to 3 cm of radius and slight ellipticity in the ring of up to 5%. Results show lower-charge weights for higher order OAM modes.

scholarly journals Biofuel-powered soft electronic skin with multiplexed and wireless sensing for human-machine interfaces

2020 ◽  
Vol 5 (41) ◽  
pp. eaaz7946 ◽  
Author(s):  
You Yu ◽  
Joanna Nassar ◽  
Changhao Xu ◽  
Jihong Min ◽  
Yiran Yang ◽  
...  
Keyword(s):  
Human Body ◽  
Power Efficiency ◽  
Near Field ◽  
Three Dimensional ◽  
Biofuel Cells ◽  
Physical Parameters ◽  
Power Intensity ◽  
Electronic Skin ◽  
Self Powered ◽  
Body Self

Existing electronic skin (e-skin) sensing platforms are equipped to monitor physical parameters using power from batteries or near-field communication. For e-skins to be applied in the next generation of robotics and medical devices, they must operate wirelessly and be self-powered. However, despite recent efforts to harvest energy from the human body, self-powered e-skin with the ability to perform biosensing with Bluetooth communication are limited because of the lack of a continuous energy source and limited power efficiency. Here, we report a flexible and fully perspiration-powered integrated electronic skin (PPES) for multiplexed metabolic sensing in situ. The battery-free e-skin contains multimodal sensors and highly efficient lactate biofuel cells that use a unique integration of zero- to three-dimensional nanomaterials to achieve high power intensity and long-term stability. The PPES delivered a record-breaking power density of 3.5 milliwatt·centimeter−2 for biofuel cells in untreated human body fluids (human sweat) and displayed a very stable performance during a 60-hour continuous operation. It selectively monitored key metabolic analytes (e.g., urea, NH4+, glucose, and pH) and the skin temperature during prolonged physical activities and wirelessly transmitted the data to the user interface using Bluetooth. The PPES was also able to monitor muscle contraction and work as a human-machine interface for human-prosthesis walking.

Improved Analytical Models for Single- and Multi-layer Silver Superlenses

2009 ◽  
Vol 1182 ◽  
Author(s):  
Ciaran P Moore ◽  
Richard John Blaikie ◽  
Matthew D Arnold
Keyword(s):  
Transfer Functions ◽  
Near Field ◽  
Single Layer ◽  
Analytical Models ◽  
Full Field ◽  
Accurate Performance ◽  
Imaging Performance ◽  
Performance Estimates ◽  
Continuous Metal ◽  
Good Agreement

AbstractSpatial-frequency transfer functions are regularly used to model the imaging performance of near-field �superlens� systems. However, these do not account for interactions between the object that is being imaged and the superlens itself. As the imaging in these systems is in the near field, such interactions are important to consider if accurate performance estimates are to be obtained. We present here a simple analytical modification that can be made to the transfer function to account for near-field interactions for objects consisting of small apertures in otherwise-continuous metal screens. The modified transfer functions are evaluated by comparison with full-field finite-element simulations for representative single-layer and multi-layer silver superlenses, and good agreement is found.

scholarly journals Low-cost wireless power efficiency optimization of the NFC tag through switchable receiver antenna

2018 ◽  
Vol 5 (2) ◽  
pp. 87-96 ◽  
Author(s):  
Yi Zhao ◽  
Huaye Li ◽  
Saman Naderiparizi ◽  
Aaron Parks ◽  
Joshua R. Smith
Keyword(s):  
Power Efficiency ◽  
Low Cost ◽  
Near Field ◽  
Power Delivery ◽  
Wireless Power ◽  
Load Impedance ◽  
Communication Performance ◽  
Sensing Platform ◽  
Varied Range ◽  
Range Alignment

Near-field communication (NFC) readers, ubiquitously embedded in smartphones and other infrastructures can wirelessly deliver mW-level power to NFC tags. Our previous work NFC-wireless identification and sensing platform (WISP) proves that the generated NFC signal from an NFC enabled phone can power a tag (NFC-WISP) with display and sensing capabilities in addition to identification. However, accurately aligning and placing the NFC tag's antenna to ensure the high power delivery efficiency and communication performance is very challenging for the users. In addition, the performance of the NFC tag is not only range and alignment sensitive but also is a function of its run-time load impedance. This makes the execution of power-hungry tasks on an NFC tag (like the NFC-WISP) very challenging. Therefore, we explore a low-cost tag antenna design to achieve higher power delivered to the load (PDL) by utilizing two different antenna configurations (2-coil/3-coil). The two types of antenna configurations can be used to dynamically adapt to the requirements of varied range, alignment and load impedance in real-time, therefore, we achieve continuous high PDL and reliable communication. With the proposed method, we can, for example, turn a semi-passive NFC-WISP into a passive display tag in which an embedded 2.7″ E-ink screen can be updated robustly by a tapped NFC reader (e.g. an NFC-enable cell-phone) over a 3 seconds and within 1.5cm range.

Electrocutaneous Pulse Rate and Pulse Width Psychometric Functions for Sensory Communications

1979 ◽  
Vol 21 (2) ◽  
pp. 241-249 ◽  
Author(s):  
Andrew Y. J. Szeto ◽  
John Lyman ◽  
Ronald E. Prior
Keyword(s):  
Pulse Rate ◽  
Pulse Width ◽  
Communication Systems ◽  
Transfer Functions ◽  
Frequency Discrimination ◽  
Just Noticeable Difference ◽  
Electrocutaneous Stimulation ◽  
Maximum Frequency ◽  
Sensory Communication

Psychometric functions of pulse rate (PR) and pulse width (PW) from electrocutaneous stimuli were determined using the method of comparative judgments. The study revealed that changes in PR were more easily detected than changes in PW, as measured by the percent of just noticeable difference (jnd). The PR jnd data from test subjects indicated that maximum frequency discrimination occurred near 20 pulses per second. Using the PR and PW psychometric curves, compensatory transfer functions can be determined which will improve the efficacy of sensory communication systems based on electrocutaneous stimulation.

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