Capacitive power transfer (CPT) system can be employed for wireless charging of drone applications. However, in the CPT system, cross-coupling capacitance caused by coupling of the two pairs of plates on different sides, which do not form the main capacitance must be considered. Designs that do not properly consider the cross-coupling capacitance can cause decrease in the efficiency of the system. In this article, we propose a separate circular capacitive coupler for the CPT system. To reduce the cross-coupling capacitance in drone applications, the plates on the same side are separated. The circuit model of the coupler is presented; it considers a total of six coupling capacitances. For maximum power transfer efficiency, impedance of the receiver is considered to determine the parameter value of the LC resonance. Through simulation and measurement, we verified that the proposed separated circular coupler can reduce the cross-coupling capacitance. The plate-to-plate power transfer efficiency is maintained at 89.4% with 100-W output power.

Recently, maintenance applications around power lines have been actively studied. These applications usually supply power through magnetic energy harvesting(MEH) to devices around the power line. A major challenge for practical MEH is to overcome magnetic saturation, which can cause degradation of power density under a wide current range in the power line. In this paper, we propose a design methodology to harvest maximized output power by considering the saturation effect. To consider magnetic saturation, the output power model and the saturable magnetizing inductance model based on magnetizing current were comprehensively analyzed. Additionally, the critical point of saturation for the maximum harvested power was analyzed by considering different primary side current conditions. With the proposed design methodology, the accuracy and efficiency of the output model were verified with experimental results compared to the conventional model. To consider the real environment, a 150 kW class of AC resistor load bank was implemented to control the primary current from 0 to 100 A with power frequency of 60 Hz. Experimental results show that the proposed method can harvest an average power of 14.32 W on 70 A power line, which is an increase of 39.8 % compared with the conventional design method.

Wireless power transfer systems are increasingly used as a means of charging implantable medical devices. However, the heat or thermal radiation from the wireless power transfer system can be harmful to biological tissue. In this research, we designed and implemented a wireless power transfer system-based implantable medical device with low thermal radiation, achieving 44.5% coil-to-coil efficiency. To suppress thermal radiation from the transmitting coil during charging, we minimized the ESR value of the transmitting coil. To increase power transfer efficiency, a ferrite film was applied on the receiving part. Based on analyses, we fabricated a cardiac monitoring system with dimensions of 17 × 24 × 8 mm³ and implanted it in a rat. We confirmed that the temperature of the wireless charging device increased by only 2 °C during the 70 min charging, which makes it safe enough to use as an implantable medical device charging system.

In this paper, we propose, analyze and design a through silicon via (TSV) with a passive equalizer (PEQ) to mitigate the inter-symbol interference (ISI) and separate the return path for next-generation high bandwidth memory (HBM). The proposed HBM TSV includes a PEQ into the region between the signal TSV and ground TSV. We suggest the two-design structure of PEQ using the inductance and resistance. The proposed HBM TSV with PEQ provides two advantages. First, ISI can be suppressed by increasing the bandwidth or reducing the reflection caused by multi-drop topology. Second, the crosstalk can be reduced by separating return paths between the different signal TSVs. Based on the analytical modeling, the physical meaning of the proposed HBM TSV is presented. The channel loss, group delay, crosstalk, and time domain waveform are analyzed in terms of signal integrity for the proposed HBM TSV. Analysis and design method of the proposed HBM TSV are suggested to find an optimization point to define the resistance, inductance, and position of the PEQ. The proposed HBM TSV is evaluated based on the eye-diagram. Finally, from the practical point of view, the proposed HBM TSV fabrication process is also described.

It is necessary to reduce the crosstalk noise in high-speed signaling channels. In the channel routing area, the tabbed routing pattern is used to mitigate far-end crosstalk (FEXT), and the electrical length is controlled with a time domain reflectometer (TDR) and time domain transmission (TDT). However, unlike traditional channels having uniform width and space, the width and space of tabbed routing changes by segment, and the capacitance and inductance values of tabbed routing also change. In this paper, we propose a tabbed routing equivalent circuit modeling method using the segmentation approach. The proposed model was verified using 3D EM simulation and measurement results in the frequency domain. Based on the calculated inductance and capacitance parameters, we analyzed the insertion loss, FEXT, and self-impedance in the frequency domain, and TDT and FEXT in the time domain, by comparing the values of these metrics with and without tabbed routing. Using the proposed tabbed routing model, we analyzed tabbed routing with variations of design parameters based on self- and mutual-capacitance and inductance.

Wireless power transfer (WPT) based microrobot maximize the utilization of microrobot since it can transfer electrical energy wirelessly. Unlikely the static magnetic field microrobot propulsion, the WPT based microrobot uses the magnetic force on magnetic material that generated by time-varying magnetic Held. Expecting and evaluating the magnetic force on a magnetic material under wireless power transfer system is important for it determines the moving velocity of microrobot. In this paper, we derive and evaluate a force on a magnetic bar-type material, which is a source of propulsion force of wireless power transfer based microrobot.