Jinwook Song

Inverter modeling including non-ideal IGBT characteristics in Hybrid Electric Vehicle for accurate EMI noise prediction

In this study, an inverter model including non-ideal Insulated Gate Bipolar Transistors (IGBTs) characteristics and a busbar model using impedance measurement is proposed. A motor drive system in Hybrid Electric Vehicle (HEV) consists of a battery, an inverter, a cable, and an electric motor. The inverter is not only a voltage source, but also one of the principal noise sources in the motor drive system. Since switching operations of power devices in the inverter make Electromagnetic Interference (EMI) noise, a non-ideal model of the IGBTs is needed for accurate EMI analysis of the motor drive system. By simulating the motor drive system with proposed non-ideal inverter model, it is possible to predict accurate common mode current noises in view of whole vehicle level. The model is verified by comparison with measurement.

Ultra-thin printed circuit board metamaterial for high efficiency wireless power transfer

Metamaterial composed of artificial periodic structure is applied to a wireless power transfer system to enhance the efficiency of long distance power transfer. Metamaterial can control the direction of magnetic fields due to its negative permeability. Previously reported metamaterials were too thick and large in size to increase the power transfer distance. In this paper, ultra-thin (0.16 cm) and small (18.6 × 18.6 cm) metamaterial structure is proposed and its enhanced efficiency (with maximum of 44.2 % improvement) is demonstrated. Furthermore, this paper shows simplified modeling method for complicated metamaterial structure simulation.

Design and analysis of magnetically coupled coil structures for PCB-to-active interposer wireless power transfer in 2.5D/3D-IC

In this study, magnetically coupled coil design for high efficiency wireless power transfer (WPT) in PCB-to-active silicon (Si) interposer is proposed and analyzed using Z-parameter analysis. For strong magnetic coupling between transmitter (Tx) coil on PCB and receiver (Rx) coil on Si-interposer, each coil structure is selected considering process dimension difference between PCB and Si-interposer. The equivalent circuit models for Tx coil on PCB and Rx coil on Si-interposer are suggested. Especially, the Rx coil model includes lossy Si-substrate characteristics and eddy current effect. In addition, analytical model for vertically aligned Tx coil and Rx coil in 2.5D/3D-IC is developed by considering LC resonance. All the proposed equivalent circuit models are analyzed by comparing Z-parameters (Z11) with 3D EM simulation results. In this coil system, series-series WPT topology is applied to achieve high power transfer efficiency (PTE) and maintain a constant resonant frequency regardless of load impedance. The resonant frequency for high PTE is decided to be 100 MHz.

Hybrid metamaterial with zero and negative permeability to enhance efficiency in wireless power transfer system

Metamaterials with negative relative permeability can change magnetic field in the opposite direction. It can also change the magnetic field direction to straight if it has zero relative permeability. Previously reported metamaterials use only single characteristic which is a negative or a zero permeability to enhance efficiency by field confinement in wireless power transfer (WPT) systems. In this paper, we combined two kinds of structures of metamaterial cells, which have the negative and zero permeability. The hybrid metamaterial slab (HMS) is designed by using two spiral type patterns on a double layered PCB. It has the negative permeability at the edge of the slab and the zero permeability at the center of the slab. The HMS can confine greater magnetic fields around and inside transmit and receive coils. Therefore, the hybrid metamaterials can increase the power efficiency by 21.4% at 20 cm distance in 6.78 MHz WPT systems compared to the previous single permeability metamaterial slab (SMS).

Analysis of high frequency characteristics of power inverter using accurate IGBT model based on datasheet and measurement

The output voltage and current from dc-ac inverter generate switching noises and may cause electromagnetic interference (EMI) problems to other electronic systems. To analyze high frequency switching behavior of an inverter accurately, an accurate IGBT model is essential. In this study, an insulated gate bipolar transistor (IGBT) is modeled using datasheet and measurement data to analyze the high frequency characteristics of a high-power full-bridge inverter. The effectiveness of the proposed IGBT model is verified by comparing the simulated results of the inverter using the proposed IGBT model with measured results in frequency domain.

Design of an on-interposer passive equalizer embedded on a ground plane for 30Gbps serial data transmission

In this paper, a new on-interposer passive equalizer was proposed for chip-to-chip high-speed serial data transmission. It is a coil-shaped shunt metal line and embedded on a ground plane to maximize channel routability. Since the proposed equalizer is based on the fine pitch design rules of silicon interposer, it can be integrated in a small area. Equalizing method is based on a high pass filter composed of an inductance and a resistance of the proposed structure. It achieves wide-band equalization up to data rate of 30 Gbps. Performance of the proposed equalizer is verified using frequency- and time-domain simulation. By applying the proposed equalizer to 30 Gbps channel, eye-height was improved by 13.4 % of input voltage and timing jitter was reduced by 5.5 % of one unit interval.

analysis of power inverter parasitic inductances effect on switching characteristics for accurate electromagnetic interference (EMI) estimation

A DC-AC power inverter contains parasitic inductances in a DC-linked wire and a load wire. These parasitic components may cause oscillation in the output voltage of the inverter, and cause electromagnetic interference (EMI) issues to other power electronic circuits in the system. In this paper, an effect of the parasitic inductances on the DC-linked wire and load wire of the power inverter are analyzed. To model the power inverter, advanced dynamic IGBT model of the ANSYS Simplorer tool which contains the information of the three parasitic capacitances between collector-gate (CCG), collector-emitter (CCE) and gate-emitter (CGE) is adopted.

Dual-directional near field communication tag antenna with effective magnetic field isolation from wireless power transfer system

Wireless power transfer (WPT) system has been developed to achieve higher charging power and convenient charging experience to users. In some mobile electronic devices with WPT system near-field communication (NFC) system can also be utilized. However, during the wireless charging, large voltage is induced in the NFC tag due to the magnetic fields from the wireless charging system. Consequently, the NFC tag must be isolated from the WPT system for simultaneous operation. In this paper, the NFC tag with dual-directional pattern antenna is presented for efficient isolation of the WPT system. The transmission coefficient between the proposed NFC tag and the NFC antenna is reduced by 3 dB at 13.56 MHz, while insertion loss between the tag and WPT coil is reduced by 18 dB at 110 kHz. Even with 10 mm misalignment between the proposed NFC tag and the WPT coils, 10 dB reduction of insertion loss can be achieved at 110 kHz.

Chip-level wireless power transfer scheme design for next generation wireless interconnected three-dimensional integrated circuits

In this paper, we propose chip-level wireless power transfer (WPT) scheme for the next generation high density wireless three-dimensional (3-D) semiconductor packaging technology. We designed a transmitter coil on an active silicon interposer embedded in a PCB-package and a receiver coil on a processor die. The proposed WPT scheme used magnetic-field resonance coupling for high power transfer efficiency. We fabricated a full-bridge rectifier and a low-dropout regulator (LDO) to make a stable DC power for a voltage-controlled oscillator (VCO) on the processor die using SK/Hynix 0.18 μm CMOS process. A VCO is key circuit block consisting of a PLL for clock generation to synchronize data transfer between a processor and a memory controller. The designed VCO successfully generated 1.6 GHz signal using the power from the proposed chiplevel WPT scheme.

Design and analysis of wireless power transfer system using flexible coil and shielding material on smartwatch strap

In this paper, we propose and analyze a smartwatch strap wireless power transfer (WPT) system using flexible PCB coils and magnetic field shielding materials. To ensure the sufficiency power delivery, we addressed the changes in impedance of the curved WPT coil system using 3D EM simulation and Z-parameter analysis. Using the proposed scheme, we achieved coil to coil power transfer efficiency of 50%.