Analysis and evaluation of input power splitting method between multiple transmitters for maximum wireless power transfer

2018 ◽  
Author(s):  
Yuan Cao ◽  
Jaber A. Abu Qahouq
Keyword(s):  
Splitting Method ◽  
Wireless Power Transfer ◽  
Input Power ◽  
Power Splitting ◽  
Power Transfer ◽  
Wireless Power ◽  
Analysis And Evaluation

scholarly journals Wireless power transfer system rigid to tissue characteristics using metamaterial inspired geometry for biomedical implant applications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ramesh K. Pokharel ◽  
Adel Barakat ◽  
Shimaa Alshhawy ◽  
Kuniaki Yoshitomi ◽  
Costas Sarris
Keyword(s):  
Electromagnetic Waves ◽  
Wireless Power Transfer ◽  
Split Ring Resonator ◽  
Input Power ◽  
Power Transfer ◽  
Wireless Power ◽  
Biomedical Implant ◽  
Safety Regulations ◽  
Wireless Power Transfer System ◽  
Tissue Characteristics

AbstractConventional resonant inductive coupling wireless power transfer (WPT) systems encounter performance degradation while energizing biomedical implants. This degradation results from the dielectric and conductive characteristics of the tissue, which cause increased radiation and conduction losses, respectively. Moreover, the proximity of a resonator to the high permittivity tissue causes a change in its operating frequency if misalignment occurs. In this report, we propose a metamaterial inspired geometry with near-zero permeability property to overcome these mentioned problems. This metamaterial inspired geometry is stacked split ring resonator metamaterial fed by a driving inductive loop and acts as a WPT transmitter for an in-tissue implanted WPT receiver. The presented demonstrations have confirmed that the proposed metamaterial inspired WPT system outperforms the conventional one. Also, the resonance frequency of the proposed metamaterial inspired TX is negligibly affected by the tissue characteristics, which is of great interest from the design and operation prospects. Furthermore, the proposed WPT system can be used with more than twice the input power of the conventional one while complying with the safety regulations of electromagnetic waves exposure.

scholarly journals Wireless Power Transfer to a Microaerial Vehicle with a Microwave Active Phased Array

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Shotaro Nako ◽  
Kenta Okuda ◽  
Kengo Miyashiro ◽  
Kimiya Komurasaki ◽  
Hiroyuki Koizumi
Keyword(s):  
Phased Array ◽  
Wireless Power Transfer ◽  
Axial Ratio ◽  
Input Power ◽  
Power Transfer ◽  
Wireless Power ◽  
Phased Array Antenna ◽  
Power Fluctuation ◽  
Microwave Beam ◽  
Yaw Angle

A wireless power transfer system using a microwave active phased array was developed. In the system, power is transferred to a circling microaerial vehicle (MAV) by a microwave beam of 5.8 GHz, which is formed and directed to the MAV using an active phased array antenna. The MAV is expected to support observation of areas that humans cannot reach. The power beam is formed by the phased array with eight antenna elements. Input power is about 5.6 W. The peak power density at 1,500 mm altitude was 2.63 mW/cm2. The power is sent to a circling MAV. Therefore, the transfer beam should be polarized circularly to achieve a constant power supply independent of its yaw angle. To minimize the polarization loss, a sequentially routed antenna (SRA) was applied to the transmitter antenna. Results show that the axial ratio of 0.440 dB was accomplished and that power fluctuation was kept below 1%.

scholarly journals Influence of Asymmetric Coil Parameters on the Output Power Characteristics of Wireless Power Transfer Systems and Their Applications

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1212
Author(s):  
Zhipeng Guan ◽  
Bo Zhang ◽  
Dongyuan Qiu
Keyword(s):  
Output Power ◽  
Lithium Ion ◽  
Wireless Power Transfer ◽  
Power Splitting ◽  
Wireless Charging ◽  
Power Transfer ◽  
Wireless Power ◽  
Asymmetric System ◽  
Power Characteristics ◽  
Portable Power

Nowadays, it is a trend to update electronic products by replacing the traditional wire charging with emerging wireless charging. However, other features of the products must generally be left unchanged, which limits the options in receiving coil design. As a result, asymmetric coil designs should be adopted in wireless charging systems. In this paper, a wireless power transfer system with asymmetric transmitting and receiving coils is modelled using circuit theory. The output power of the asymmetric system is analyzed, and the conditions of the maximum power splitting phenomenon are addressed in detail. Cases for different resonant frequency conditions are elaborated. The splitting frequencies and critical coupling coefficient are obtained, which are different and more complicated compared with the symmetric counterparts. Asymmetric coil designs can be adopted based on the proposed method, so that adequate and efficient output power transfer can be realized. Finally, the asymmetric coils design is utilized in an experimental prototype in order to contactlessly charge a portable power tool lithium-ion battery pack with 18 V DC and 56 W output through 220 V AC input, without altering its original configuration, and the correctness of proposed analysis can thus be verified.

scholarly journals A Circularly Polarized Implantable Rectenna for Microwave Wireless Power Transfer

Micromachines ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 121
Author(s):  
Chao Xu ◽  
Yi Fan ◽  
Xiongying Liu
Keyword(s):  
Wireless Power Transfer ◽  
Axial Ratio ◽  
Input Power ◽  
Impedance Bandwidth ◽  
Power Transfer ◽  
Wireless Power ◽  
Circularly Polarized ◽  
Rectangular Slot ◽  
Dc Power ◽  
Implantable Antenna

A circularly polarized implantable antenna integrated with a voltage-doubled rectifier (abbr., rectenna) is investigated for microwave wireless power transfer in the industrial, scientific, and medical (ISM) band of 2.4–2.48 GHz. The proposed antenna is miniaturized with the dimensions of 7.5 mm × 7.5 mm × 1.27 mm by etching four C-shaped open slots on the patch. A rectangular slot truncated diagonally is cut to improve the circular polarization performance of the antenna. The simulated impedance bandwidth in a three-layer phantom is 30.4% (1.9–2.58 GHz) with |S11| below −10 dB, and the 3-dB axial-ratio bandwidth is 16.9% (2.17–2.57 GHz). Furthermore, a voltage-doubled rectifier circuit that converts RF power to DC power is designed on the back of the antenna. The simulated RF-to-DC conversion efficiency can be up to 45% at the input power of 0 dBm. The proposed rectenna was fabricated and measured in fresh pork to verify the simulated results and evaluate the performance of wireless power transfer.

scholarly journals A 2.45 GHz FSS Loaded Rectifying Antenna

2021 ◽  
Author(s):  
UDAYABHASKAR PATTAPU ◽  
Sushrut Das
Keyword(s):  
Wireless Power Transfer ◽  
Input Power ◽  
Maximum Efficiency ◽  
Power Transfer ◽  
Wireless Power ◽  
Free Response ◽  
Dc Voltage ◽  
Received Power ◽  
Polarization Insensitive ◽  
Antenna Impedance

Abstract In this paper the development of a rectenna system has been presented for 2.45 GHz wireless power transfer application. The receiving element of the rectenna (or the antenna) has been designed to possess spurious free response at least up to 10 GHz to improve the RF-DC conversion efficiency. It was found that the gain of the antenna is not sufficient for rectenna application. Therefore, to improve the gain of the antenna, it has been loaded with an angle and polarization insensitive FSS. The FSS loaded antenna achieved 7.7 dB gain, 85% radiation efficiency, and single operating band at 2.45 GHz; which is suitable for developing a rectenna for wireless power transfer. To convert the received RF energy into DC voltage a 2.45 GHz matched rectifier circuit has been designed. L-type matching network has been used to match the complex rectifier impedance with the 50 Ω antenna impedance. 1.52 V output voltage was obtained for 7 dBm input power and 3 kΩ load. Achieved maximum efficiency is 66.13% for 1.1 mW received power. It has been shown that the FSS loading of the antenna has the capacity of drastically improve the efficiency of the rectenna system.

scholarly journals A High-Efficiency Self-Synchronous RF–DC Rectifier Based on Time-Reversal Duality for Wireless Power Transfer Applications

Electronics ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 90
Author(s):  
Ying Wang ◽  
Gao Wei ◽  
Shiwei Dong ◽  
Yazhou Dong ◽  
Xumin Yu ◽  
...  
Keyword(s):  
Time Reversal ◽  
High Efficiency ◽  
Design Method ◽  
Wireless Power Transfer ◽  
Operating Mode ◽  
Load Resistance ◽  
Input Power ◽  
Adjustment Process ◽  
Power Transfer ◽  
Wireless Power

An RF–DC rectifier is an important part in a wireless power transfer system. Diode-based rectifiers are widely used in low-power harvesting scenarios, and for high power, a transistor based on the time-reversal duality was proposed. This paper presents a high-efficiency self-synchronous RF–DC rectifier based on a waveform-guided design method and an improved rectification model of a commercial GaN device. The main contributions of this paper are that (1) an improved transistor model with correct reverse bias is built for accurate rectifier simulation, and (2) a new design method of self-synchronous RF–DC rectifier is proposed: as soon as the operating mode of the rectifier, input power, and DC load are set, matching and coupling network can be calculated directly based on waveform-guided method, thus design and adjustment process of a conventional power amplifier (PA) due to the duality between a PA and a rectifier would no longer be required. A 5.8 GHz self-synchronous RF–DC rectifier is designed for validation, and the optimum RF–DC conversion efficiency is 68% with 12 W input power as well as 19.9 V output DC potential with 50 Ω load resistance. The proposed rectifier is suitable for high input power rectification applications of wireless power transfer.

scholarly journals Implement of multiple access technique by wireless power transfer and relaying network

2021 ◽  
Vol 10 (2) ◽  
pp. 793-800
Author(s):  
Anh-Tu Le ◽  
Dinh-Thuan Do
Keyword(s):  
Multiple Access ◽  
Performance Metrics ◽  
Signal To Noise Ratio ◽  
Wireless Power Transfer ◽  
Base Station ◽  
Power Splitting ◽  
Power Transfer ◽  
Wireless Power ◽  
Amplify And Forward ◽  
Decode And Forward

In this paper, we investigate non-orthogonal multiple access (NOMA) network relying on wireless power transfer to prolong lifetime. The base station (BS) sends common signals to the relay with two functions (energy harvesting (EH) and signal processing) to further serve two NOMA users in downlink. Performance gap exists since different power allocation factor assigned from power splitting protocol adopted at the relay and such relay employs both amplify-and-forward (AF) and decode-and-forward schemes. To provide performance metrics, we prove formulas of the outage probability which is a function of transmit signal to noise ratio. Simulation results indicate specific parameters to adjust system performance of two user in the considered EH-NOMA system. This finding is important recommendation to design EH-NOMA which shows particular outage performance at required target rates.

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