Effect of Layer Spacing and Line Width of PCB Coil on Resonant Frequency

Abstract

With the development of electronic science and technology, people have entered the information society, a variety of portable electronic products enter people’s lives. A large number of miniature human implantable medical devices applied to clinical fields. The traditional human implantable medical device power supply is implanted battery, its biggest drawback is the treatment problem after the battery power consumption. Whether it is taken to replace the new battery, or deep into the body, there is a huge risk. Therefore, the portable external wireless charging, it becomes the best choice for human implantable medical devices. Because some of the implanted device volume is very small, they can't accommodate bulky solenoid coil, which seriously restrict the application of wireless charging technology in implantable medical devices. Printed circuit board (PCB) coil has the advantages of high wiring density, small volume, light weight, beneficial to the miniaturization of electronic equipment, they can replace traditional solenoid coil, and applied to the wireless charging technology. In this paper, HFSS software is used to simulate, a large number of simulation experiments are carried out on the PCB with 2 layers coils. At the same time, the electrical parameters such as layer spacing, line width and resonant frequency are analyzed. Finally, the conclusion is: in the case of fixed layer spacing, with the increasing of the line width, the resonance frequency is gradually reduced; but the resonance frequency is reduced to a certain extent, it is not changed. When line width is fixed, with the growing layer spacing, the resonance frequency value is constantly increasing, the resonant frequency of the growth is also more and more slow.