Haokun Chi

Simulation Analysis of Efficiency of Wireless Power Transmission System for AUV

Adequate electrical energy can guarantee long-term navigation for the autonomous underwater vehicle (AUV). Compared with the traditional wired charging method, wireless charging has the advantages of high security, simple operation and so on, and is more suitable for underwater application. In this paper, we study the efficiency of wireless power transmission (WPT) system in air and seawater. The transmission efficiency of wireless transmission system in air and seawater is compared with HFSS simulation. The reason of system efficiency decay is analyzed, which is helpful for the application of wireless power transmission technology in AUV.

Simulation Analysis of Influencing Factors for Resonant Frequency of PCB Coil Based on HFSS

In recent years, the application of implantable medical devices has become increasingly popular, and its power supply problem has become a hot research, and the problem of its energy supply is also a research hot topic. The PCB (printed circuit board) coils can be used to achieve cascading and stacking between adjacent layers in very small volumes, so they are very suitable for implantable applications.

Analysis of SAR distribution in human head of antenna used in wireless power transform based on magnetic resonance

In this paper, a novel wireless power transfer antenna system was designed for human head implantable devices. The antenna system used the structure of three plates and four coils and operated at low frequencies to transfer power via near field. In order to verify the electromagnetic radiation safety on the human head, the electromagnetic intensity and specific absorption rate (SAR) were studied by finite-difference-time-domain (FDTD) method. A three-layer model of human head including skin, bone and brain tissues was constructed. The transmitting and receiving antenna were set outside and inside the model. The local and average SAR were simulated at the resonance frequency of 18.67 MHz in two situations, in one scenario both transmitting and receiving coil worked, while in the other scenario only the transmitting coil worked. The results showed that the maximum of 10 g SAR average value of human thoracic were 0.142 W/kg and 0.148 W/kg, respectively, both were lower than the international safety standards for human body of the ICNIRP and FCC, which verified the safety of the human body in wireless power transmission based on magnetic coupling resonance.

Influencing Factors of Inductance for 3D Micro-PCB Rectangular Coil

The main constraint that restricts wireless charging technology successfully applied in miniature medical electronic equipment is that the volume of the transmission coil is difficult to reduce. The printed circuit board (PCB) coil can take advantage of multi-layer wiring space to achieve the coil stack, achieving the purpose of increasing the relative magnetic flux, so that it could replace the traditional spiral coil to become the medium of wireless power transmission in the mini-medical electronic device. In this paper, we analyzed several electrical parameters that could affect the 3D PCB rectangular coil inductance value based on the 3D PCB rectangular coil inductance computing method. Then we sort these influencing factors so that these results can help designers to design the 3D PCB coil. The conclusions are as follows: (1) number of layers, total number of turns have positive correlation with the self-inductance; metal width, substrate thickness, the pitch between adjacent turns have negative correlation with the self-inductance. (2) The sorting of influencing factors of the inductance is as follows: total number of turns>number of layers, the pitch between adjacent turns>substrate thickness>metal width.

Analysis of the multi-layer Printed Spiral Coil for wireless power transfer system used in medical implants

The performance of the wireless power transfer (WPT) system is highly constrained by the coils in the coupling field. The coils can be fabricated as multi-layer Printed Spiral Coil (PSC) due to the development of the Printed Circuit Board (PCB) technique. This spatial effective coil implements the miniaturization for medical implants with higher inductance and lower resonance frequency. The accurate design of the PSC will be extremely complex with the analytical derivation based on Maxwells equations. In this work, we proposed a new formula to connect the geometrical parameters with the self-resonance frequency and the Q-factor of the PSC. The numerical and experimental method are used to analysis the factors in our formula. We find that the resonance frequency is very sensitive to the number of turns and layers in the PSC. This mathematical method provides a more accurate approach for the coil design and optimization.