Search

In this article, for the first time, we propose channel characteristic-based deep neural network (DNN) models for accurate eye-height (EH) and eye-width (EW) estimation of high bandwidth memory (HBM) silicon interposer channels. The proposed models preprocess the design parameters that are highly relevant to the characteristics of the HBM channels. By taking account of the contribution of each design parameter to the eye diagram, the proposed models can accurately estimate the EH and EW of the channels even with a limited number of datasets. For verification, the proposed DNN models were applied to the microstrip and stripline channels of an HBM silicon interposer. Only redistributed layer (RDL) was used to clearly see the effect of reflecting the channel characteristics of the proposed method. We compared the proposed DNN models with various regression methods and a conventional fully connected multilayer DNN model. As a result, the proposed DNN models reduced the EH and EW error rates by 22.7 and 43.9% compared to the other regression methods. In addition, the proposed DNN models not only reduced the error rates by 22.0–28.4% but also reduced the computing cost by 8.0–9.4%, compared to the conventional DNN model. Moreover, we compared the proposed models with various DNN models having other preprocessing structures. By showing 26.7 and 28.8% lower EH and EW error rates than the other DNN models, we validated that the proposed models properly consider the most dominant design factors in preprocessing.

In this article, we propose a near field analytical model of an electromagnetic interference reduction method using an n th harmonic frequency shielding coil with efficiency enhancement in a loosely coupled automotive wireless power transfer system. In general, in the loosely coupled automotive wireless power transfer system, the power transfer efficiency is relatively lower than a tightly coupled wireless power transfer system due to the low coupling. In addition, the electromagnetic interference at the n th harmonic frequency from the power source can interfere with nearby electronic devices. To reduce electromagnetic interference level and enhance efficiency, we proposed a shielding coil between a transmitter and a receiver coil. By using a near field analytical model of the magnetic field intensity and efficiency equations, we analyze based on the equations and obtain a proper value of the resonant frequency of the shielding coil. Therefore, we can achieve low levels of electromagnetic interference at the specific n th harmonic frequency and higher value of the power transfer efficiency in the loosely coupled automotive wireless power transfer system.

In this article, we first propose a deep reinforcement learning (RL)-based optimal decoupling capacitor (decap) design method for silicon interposer-based 2.5-D/3-D integrated circuits (ICs). The proposed method provides an optimal decap design that satisfies target impedance with a minimum area. Using deep RL algorithms based on reward feedback mechanisms, an optimal decap design guideline can be derived. For verification, the proposed method was applied to test power distribution networks (PDNs) and self-PDN impedance was compared with full search simulation results. We successfully verified by the full search simulation that the proposed method provides one of the solution sets. Conventional approaches are based on complex analytical models from power integrity (PI) domain expertise. However, the proposed method requires only specifications of the PDN structure and decap, along with a simple reward model, achieving fast and accurate data-driven results. Computing time of the proposed method was a few minutes, significantly reduced than that of the full search simulation, which took more than a month. Furthermore, the proposed deep RL method covered up to $10^{17}$ – $10^{18}$ cases, an approximately $10^{12}$ – $10^{13}$ order increase compared to the previous RL-based methods that did not utilize deep-learning techniques.

Current wireless power transfer (WPT) technology is widely used for various applications because of convenience and safety. However, WPT systems have problems with electromagnetic field (EMF) leakage, which can cause electromagnetic interference (EMI) issues for nearby electrical devices at various frequency ranges. In the case of the Qi standard that operates from 105 to 205 kHz frequency range, the third or fifth harmonic can cause EMI problems for the amplitude modulation bands of a radio corresponding from 530 to 1700 kHz. For the first time, in this article, we propose a frequency-selective EMI reduction method with an additional shielding coil for the effective suppression of EMI radiation of a WPT system. The proposed method reduces the EMI in a specific frequency range and has insignificant effect on the power transfer efficiency (PTE). We experimentally verified that the proposed method with the shielding coil reduced the EMF leakage by 8.96 dB of the third harmonics without reduction of the PTE. Furthermore, we mathematically designed the shielding coil using the proposed method. The mathematical calculation based on the equivalent circuit models is strongly correlated with the experimental measurement results.

In this paper, for the first time, we propose a noise suppression scheme for automotive controller area networks with flexible data rate (CAN-FD) networks that is using series damping resistor-equipped joint connectors (JCs). A CAN-FD is a bus protocol that allows multiple electrical control units (ECUs) to cross-communicate. Signal reflections at the numerous nodes and branches propagate across the entire network and considerably reduce the signal integrity of the communication. The resistors installed in series with signal pins of JCs can attenuate the signal reflection at the expense of DC power loss. We extracted S-parameter models of interconnects of a CAN-FD network, i.e., twisted pair cables, JCs, and configured them with ECU circuit models. We ran time-domain simulations, and evaluated the performance of the JCs by observing the eye diagrams between the ECUs. By equipping optimal size of resistors, the JCs could improve the width of the eye diagrams compared to the JCs without series damping resistors with an expense of DC margin.

Usually, modeling takes a long time because it depends on the engineer's experience and is done through repetitive tuning. In this paper, we propose a deep neural network (DNN)-based lumped circuit modeling method using an impedance curve. The proposed method provides a fast and accurate electrical circuit model of inductance (L), capacitance (C), and conductance (G) using a DNN. Since the LCG parameters are predicted by the impedance curve, it is flexible for various applications. For accurately predicting lumped circuit parameters, the DNN model is designed and trained through various case studies. As a result, the proposed method predicts 100% accuracy in inductance and conductance, and 92% accuracy in capacitance. In other words, the proposed method successfully models the electrical characteristics of various applications.

In this paper, we firstly proposed and electrical and thermal co-analyzed a novel through mold plate (TMP) for thermal management of high bandwidth memory (HBM). Thermal issues are bottlenecks in the development of HBM and 2.5-D/3-D ICs. The proposed TMP can be one of the promising solutions for advanced thermal management. Thermal coupling from the graphic processing unit (GPU) is the dominant factor for HBM thermal issues. A new thermal path can be achieved by installing the TMP in the epoxy molding compound (EMC) between GPU and HBM to significantly prevent thermal coupling from the GPU. By using 3D electromagnetic and fluent simulation, we verified the proposed TMP based on co-analysis of signal integrity (SI) and thermal integrity (TI). SI analysis considering both TMP and operating temperature provided the thermal and electrical superiority of TMP. As a result, the results showed the improvement of thermal integrity and signal integrity of the HBM by not only reducing HBM junction temperature by 10.3 °C but also decreasing jitter by 4.54 % compared to a conventional HBM graphic module.

In this paper, we propose a convolutional neural network (CNN)-based irregular shape power/ground impedance estimation method. For the given input power/ground (P/G) plane structure, the proposed method can estimate self impedance in a fast and accurate manner. Similar to the images represented in 2D matrices whose element values indicate the brightness, we represented shape and the dimension of the P/G plane in 2D matrices. Hence, CNN can be applied to estimate P/G plane impedance which is suitable to and outperformed in the image process. Once, CNN model is trained with numerous training data sets, the inference of P/G impedance can be performed in a few milliseconds (ms). For verification, we compared the estimated P/G plane impedance by the proposed method with the conventional 3-dimensional electromagnetic simulation results. As a result, we confirmed that the average error at each frequency is about 0.44% compared to 3-dimensional electromagnetic simulation. Moreover, unlike 3-dimensional electromagnetic simulation which required 10 minutes, the proposed method took 5.4 ms resulting in a 99.99 % reduction of computing time.

In recent years, wireless power transfer (WPT) technology is becoming an increasingly important part of the various applications because of its safety. Especially, medical implant devices such as a cochlear implant are one of the typical application of the WPT technology. Because of the individual body differences, however, the coupling coefficient of the WPT system can be changed. Therefore, the coupling coefficient-insensitivity is very important design issue.In this paper, we propose an stagger tuning method of a cochlear implant WPT system. The proposed method makes the cochlear implant WPT system stable at the link gain regardless of the coupling coefficient. In addition, the design can be optimized Λvith consideration of the power transfer efficiency (PTE) of the WPT system. We verified that the proposed method increased the PTE of the cochlear implant WPT system by 9 % by mathematical calculation.

In this paper, we proposed a deep neural network (DNN)-based estimation of efficiency enhancement by an intermediate (Int) coil in automotive wireless power transfer (WPT) system. The Int coil can enhance the efficiency in the WPT system with the proper resonant frequency of the Int coil. The previous study has explained the resonant frequency of the Int coil should be higher than the operating frequency. According to the resonant frequency of the Int coil, we can achieve the amount of efficiency enhancement. Therefore, the design of the Int coil is essential for optimize the efficiency enhancement of the automotive WPT system. However, it is impossible to achieve the optimize results of efficiency enhancement by simulations. The proposed DNN-based estimation method can predict the amount of the efficiency enhancement in real cases consisted of ferrites and shielding structures.

In this paper, we proposed a deep neural network (DNN)-based estimation of EMI reduction by an intermediate (Int) coil in automotive wireless power transfer (WPT) system. The Int coil can reduce electromagnetic interference (EMI) level in the WPT system with the proper resonant frequency of the Int coil. The previous study has explained the resonant frequency of the Int coil should be higher than the operating frequency. According to the resonant frequency of the Int coil, we can achieve the amount of EMI reduction. Therefore, the design of the Int coil is essential for optimization of the EMI reduction of the automotive WPT system. However, it is impossible to get the optimized results of EMI reduction by simulations. The proposed DNN-based estimation method can predict the amount of reduced EMI level in real cases consisted of ferrites and shielding structures.

Wireless power transfer (WPT) technology is widely used for various applications because of convenience and safety. Especially, medical implant devices such as a cochlear implant are one of the typical application of the WPT technology. However, WPT systems have problems with electromagnetic field (EMF) leakage, which can cause electro-magnetic interference (EMI) issues in the human body. In this paper, we propose an additional shielding coil for the effective suppression of EMF radiation of a WPT system. The proposed method reduces the EMF leakage in operating frequency range. We verified that the proposed shielding coil reduced the EMF leakage by 5.1 dB using 3D EM simulation. Also, the power transfer efficiency (PTE) and link gain stability of the proposed cochlear implant WPT system are designed to work well with proposed shielding coil.

In this paper, we first propose a fast and accurate deep neural network (DNN) model extension method for signal integrity (SI) applications. Reusing pre-trained weights of DNN model, the model can be extended when new training data are given. Instead of updating whole weights of DNN in traditional machine learning (ML) approaches, fine-tuning of a part of weights can accelerate training. For verification, we applied the proposed method to regression model of peak time domain reflectometry (TDR) impedance of through hole via (THV) and classification model of through silicon via (TSV) void defects. Training time of the proposed method were 0.3 s and 2.3 s respectively, which are 99 % and 82.3 % reduction compared to the traditional approach. Moreover, test accuracy of the proposed method achieved 99.2 % and 100 %, respectively.

In this paper, on-chip interconnections with an ultra-thin silicon (Si) chip for flexible electronics is modeled and verified through 3D EM simulation and measurement. To achieve flexibility of the chip, we grind a Si substrate to 15 μm. When the Si substrate is extremely thin, the lossy Si substrate effect can be reduced. Moreover, we place a ground plane on the top of the Si substrate to further reduce the Si loss. The interconnection lines are designed with the HFSS 3D EM simulation by changing design variables with 50 ohm matching impedance. In addition, we conduct an equivalent circuit modeling of the interconnection line based on RLGC components. The insertion loss (S 21 ) result of the model is then verified with the simulation and measurement results when we ignore the effect of the Si substrate. Finally, the modeling result showed good correlation with the simulation and measurement. From the experiments, we conclude that the flexible chip can be modeled with the simple interconnection RLGC model when the Si thickness is extremely thin and well designed.

In this paper, we propose a noise coupling analysis method for electronic safety and arming device (ESAD) based on a 3D-electromagnetic simulation. To analyze dominant noise coupling path in the ESAD, we propose two types of simulation methods. Theses method are based on electromagnetic field detection probes. First simulation method is to ground the target victim signal trace to the ground plane. The other method is to make the target victim signal path open circuit. Based on the proposed simulation methods, we can clarify dominant noise coupling path in the PCB of ESAD. For verification, we applied proposed simulation method on various case that can affect capacitive and inductive noise coupling in the PCB. When the dielectric constant and the conductivity of the PCB were changed, the conductivity only affected noise coupling at frequency range where inductive coupling was dominant, and the change of dielectric constant of PCB was affected at frequency range where capacitive coupling was dominant.

In this paper, we propose and analyze an double-eight shielding coil for a solenoid coil in loosely-coupled wireless power transfer (WPT) system. We suggest the shielding coil to get lower level of electromagnetic field (EMF) for the solenoid coil. The proposed double-eight shaped shielding coil, which are placed beside a transmitter (Tx) coil. The shielding coil is used to confine the leakage magnetic flux from the Tx coil and reduce the EMF. Furthermore, in the WPT system with the shielding coil, the equation of the resonant frequency condition is derived from the equivalent circuit. Using the proposed shielding coil, we reduced the EMF level by 9.3 dB scale.

Current wireless power transfer (WPT) technology is widely used for various applications because of convenience and safety. One of the typical application of the WPT system is the near-field communication (NFC) system utilized mobile WPT system. However, WPT systems have problems with electromagnetic field (EMF) leakage which can cause electromagnetic interference (EMI) issues on the nearby electrical devices. In this paper, we propose the dual resonance NFC coil for EMF reduction. Proposed dual resonance coil generates resonance not only at the NFC operating frequency of 13.56 MHz but also at the wireless charging frequency 130 kHz. When comparing the proposed NFC coil with a typical NFC antenna, the total EMF level of the WPT system is reduced by 3.96 dB at 130 kHz without any effect at the NFC operating frequency of 13.56 MHz.

The fundamental frequency approximation (FFA) for power transfer is commonly used to linearize a wireless power transfer (WPT) system which is equipped with non-linear switching converters such as a Class D inverter and rectifier. However, the FFA for power transfer disables us to analyze harmonics in a WPT system. The system characteristics only at the fundamental frequency can be analyzed with the FFA.In this paper, a new FFA for induced voltages is proposed so that analytical expressions of differential-mode voltage and current harmonics in a loosely-coupled series-resonant WPT system can be derived. Fourier series representations of the coil currents, inverter-output voltage, and rectifier-input voltage are derived and verified experimentally.

In this paper, we proposed a two-stack hybrid metamaterial slab to enhance the power transfer efficiency in wireless power transfer (WPT) system. A hybrid metamaterial is consist of zero magnetic permeability unit cells and negative magnetic permeability unit cells. Previous research shows that a hybrid metamaterial slab slightly enhances power transfer efficiency of WPT system. We first used a two-stack hybrid metamaterial slab and it shows considerably the enhanced power transfer efficiency compared to one hybrid metamaterial case. We verified the power transfer efficiency with S-parameter measurement. Thus, we finally achieved maximum 25.4% efficiency enhancement when the distance between Tx and Rx coils is 15 cm, and in overall distance variation cases, the proposed two-stack hybrid metamaterial slab make the power transfer efficiency increase.

In this paper, we have studied series-series (SS) topology and designed a band pass filter modified series-series (BF-SS) topology to reduce the electromagnetic interference (EMI) for a digital television (DTV) wireless power transfer (WPT) systems. The EMI is one of the most important and serious issue for the package system which degrades the performances of the electronic devices. The modified topology consists of a band pass filter in parallel and series of a load resistance (R L ) and a capacitance (C), respectively of a receiving (Rx) coil. Amalgamating the advantages of series-series topology, high efficiency in a small load system, and a band pass filter, filtering frequencies of useful range, our BF-SS topology has shown promising results in reducing EMI. By keeping 30 cm distance between a transmitting (Tx) coil and a Rx coil, 0.1 coupling coefficient, 145 kHz operational frequency, and $\mathrm {R} _{\mathrm {L}}\ 70\ \Omega $; we observed significant reduction in the 3rd, 5th and 7th Rx current harmonics using BF-SS topology by 6.93 dB, 17.05 dB and 17.23 dB respectively maintaining 150W load power. Moreover, we observed high coil to coil power transfer efficiency (PTE) of 96.03 % through BF-SS topology. This reduction of 3rd, 5 th and 7th Rx current harmonic reduces EMI interference.

In this paper, we design and analyze flexible wireless power transfer (WPT) coils for flexible wearable devices. The 3 cm by 3 cm flexible coils are designed using polyimide substrate. The coil is designed as thin as possible to achieve higher Q-factor and power transfer efficiency (PTE). Furthermore, we analyzed the mutual inductance between the coils with a bending radius of a receiver (Rx) coil of infinite, 26 mm and 13 mm by considering the curvature of the human wrist. As the results, the simulation results of the flexible coil are verified with the measurement results using Z-parameter analysis in the frequency range from 1 MHz to 50 MHz. In conclusion, we verify the mutual inductance simulation results with the measurement results within the average error of 2.85%.

In this paper, we propose and analyze an ultra-thin digital TV wireless power transfer (WPT) system. We suggest core-shared-repeater (CSR) coils to get higher performance in terms of coil to coil wireless power transfer efficiency (PTE) and lower electromagnetic interference (EMI). However, it is difficult to achieve higher PTE and lower EMI level due to 50 cm long air-gap, low operating frequency, and compact size of the transmitter (Tx) and receiver (Rx) structures. Therefore, we have proposed two core-shared-repeater (CSR) coils, which are placed on a ferrite core of the Tx coil. The CSR coils are used to confine the leakage magnetic flux from the Tx and transfer to the Rx coils. Furthermore, two CSR coils can be utilized to reduce the 3rd current harmonic by applying a resonant frequency of the CSR coils slightly smaller than three times of operating frequency. Using the proposed WPT system, we improved the coil to coil PTE from 61.8% to 83.9% and reduced the 3rd Rx current harmonic by 19.16 dB scale.

In this paper, we proposed an intermediate coil to reduce third harmonic EMI component, which is the highest harmonic EMI component in wireless power transfer (WPT) system. WPT system transfers power wirelessly from Tx coil to Rx coil. When Tx part driving power, unwanted harmonic components are generated from inverter of Tx part and rectifier of Rx part. The proposed intermediate coil can effectively lower third harmonic component without degrading the WPT system efficiency. Three-dimensional electromagnetic simulation and circuit simulation are used to verify the effect of the proposed intermediate coil. Thus, we finally achieved the optimal intermediate coil, which reduce third harmonic component nearly 3 dB with 2% increase in system efficiency