Modeling multi-layer via structure using PEEC method

In this dissertation, a new integral equation formulation for via structures is developed for the capacitance extraction between vias and planes. The proposed method can be used to calculate the shared-antipad via structure which is widely used in highspeed differential signal interconnects. In addition, we use the image theory to handle inhomogeneous media. Further, a new technique is given to reduce computational resources for via-to-plane structures based on properties of the matrix coefficient. The extracted capacitance is also incorporated into the physics-based circuit model to characterize the overall performance of the via transition. In the second paper, a rigorous modeling of the shared-antipad via structure is developed using surface partial element equivalent circuit (PEEC). The cavity Green\u27s function is used to evaluate the equivalent circuit elements, thereby requiring fewer cells for numerical computation. The non-orthogonal, quadrilateral cell is used in the mesh to better accommodate the non-rectangular shape of the via and the antipad. A novel wave port excitation method is applied to the equivalent circuit to obtain the network parameters of the via transition. The Z-parameters of the via structure are calculated using the proposed method, and the results are validated with the finite element solution obtained from commercial software. In the third paper, an effective methodology is proposed to estimate the RF interference received by an antenna due to near-field coupling using divide-and-conquer based on reciprocity. The proposed methodology fits well with engineering practice, and is particularly suitable for pre-layout wireless system design and planning --Abstract, page iv

Switched-Capacitor Voltage Doubler Design Using 0.5 μm Technology

While integrated circuit (IC) power management has been an eternal topic for chip designers, inductor based DC-DC converters have been dominant in the field for years. However, because of the natures of inductors: large electro-magnetic interference, high coupling noise, and difficult silicon fabrication process, they are not favorable to on-chip solutions. Switched-capacitor (SC) DC-DC converters, which adopt capacitors for their energy storage components, have become increasingly popular among both the academia and the industry, because, apparently, they avoid the drawbacks of the inductor counterparts, and can be directly implemented on-chip without additional fabrication process. In this paper, we will investigate one of the most famous SC voltage doubler topologies, which is known as Favrat Cell . By designing a chip, which converts 1.5 V voltage input to 2.5 V voltage output at 1 mA current load, we will walk through the details of a SC DC-DC converter design, including the switch cell, timing system, regulation loop and efficiency analysis. The design uses two 200 pF pumping capacitors and a 400 pF output capacitor in On-Semi half-micron technology. Four-way interleaved phase structure is adopted to reduce the output voltage ripple. The gate-drive strategy of the switches has been improved to further reduce the reverse current injections during transitions. A new high-ratio voltage booster topology based on the cross-coupled topology has been introduced and will be discussed in comparison with the Dickson charge pump topology

Grounding Structure Designs that Mitigate Undesired Resonances in High-Speed Signals

This publication discusses a specific ground-signal-signal-ground (GSSG) configuration of a high-speed differential signal pair. Simulations show that frequency resonances occur when a quarter-wavelength resonant structure is unintentionally created, which causes the observed frequency resonances. To remove the resonances, this publication recommends two design methods. Each proposed method has its own benefits and limitations. The proposed solutions may be treated as design rules for similar high-speed differential signal pairs

Equal Incremental Cost-Based Optimization Method to Enhance Efficiency for IPOP-Type Converters

Systematic optimization over a wide power range is often achieved through the combination of modules of different power levels. This paper addresses the issue of enhancing the efficiency of a multiple module system connected in parallel during operation and proposes an algorithm based on equal incremental cost for dynamic load allocation. Initially, a polynomial fitting technique is employed to fit efficiency test points for individual modules. Subsequently, the equal incremental cost-based optimization is utilized to formulate an efficiency optimization and allocation scheme for the multi-module system. A simulated annealing algorithm is applied to determine the optimal power output strategy for each module at given total power flow requirement. Finally, a dual active bridge (DAB) experimental prototype with two input-parallel-output-parallel (IPOP) configurations is constructed to validate the effectiveness of the proposed strategy. Experimental results demonstrate that under the 800W operating condition, the approach in this paper achieves an efficiency improvement of over 0.74\% by comparison with equal power sharing between both modules

Dipole-Moment-Based Reciprocity For Practical Desensitization Identification And Mitigation

Radio frequency interference can degrade the receiving sensitivity of antennas. The interference is usually caused by certain coupling structures, such as layouts without adequate grounding for the radio frequency signal return path. Those structures can be modeled as a set of equivalent dipole moments when they are electrically small. Herein, the dipole moment model-based coupling framework is applied to a practical cellphone design case to devise an engineering solution. The coupling framework incorporates dipole moments as radiation sources and a coupling model based on the reciprocity theorem. Unfortunately, near-field scan probes often lack access to all locations, owing to the complex phone platform structure. A combined measurement-simulation method is used to obtain the field quantities lacking direct access to measurements. The dipole-moment-based coupling framework helps estimate the couplings from different noise sources individually. Thus, the priority of solving for better layout designs can be determined according to the coupling estimations. Furthermore, the physics associated with the reconstructed dipole moment can provide insights and suggest possible mitigation methods. Several practical mitigation methods are discussed, including the suppression of the dominant noise source (reducing/cancelling the radiation or suppressing the specific noise spectrum) and the coupling path to the victim antenna

TECHNIQUES TO REDUCE THE RISK OF MALICIOUS OPERATIONS BEING PERFORMED DURING REMOTE CONTROL OF NETWORK DEVICES

Remote logins to network devices, such as during remote support sessions, can potentially introduce the risk of harm to network devices through human errors that could be triggered by technical support personnel during such remote logins/support sessions. Presented herein are techniques that can be implemented to fundamentally reduce the risk of human error that may occur during remote control of network equipment

An Analysis on the Effectiveness of 2 and 3 Terminal Capacitors in PDN Design

The Parasitic Inductance of a Capacitor Depends on its Physical Structure. Due to the Geometry of 3-Terminal Capacitors, They Boast a Lower Parasitic Inductance Compared to 2-Terminal Capacitors of the Same and Possibly Smaller Package Sizes. While the Parasitic Inductance of a Single 3-Terminal Capacitor May Be Lower, using Multiple 2-Terminal Capacitors May Result in Similar Performance. in This Work, the Inductance of 2-Terminal (0201, Nominal 2.2 UF) and 3-Terminal (0402, Nominal 4.3 UF) Capacitors is Extracted and Compared through Measurements. from Our De-Embedding Method and Characterized Capacitors, the Inductance of 2-Terminal Capacitors is Only About 20 PH Higher Than the Characterized 3terminal Capacitor. on a Power Net of a Real Product, 3-Terminal Capacitors of the Same Type as Characterized Were Replaced with 2-Terminal Capacitors of the Same Type as Characterized. from Measurement Results, the Measured Inductance at 100 MHz is Lower by Only About 3.45 PH, or 2.62%, When using 3-Terminal Capacitors

Augmented Genetic Algorithm V2 with Reinforcement Learning for PDN Decap Optimization

Genetic Algorithms (GAs) Use Many Hyperparameters, and Tuning These Parameters Can Determine the Optimization Performance. a GA with an Augmented Initial Population Was Proposed for Decap Optimization but It Had Convergence Issues by Getting Stuck in the Local Minimum. This Work Uses a Reinforcement Learning (RL) Approach to Adaptively Tune the Hyperparameters of GA during its Operation. with This Approach, the Agent Tries to Change the Parameters So that the GA Does Not Get Stuck in the Local Minimum. the Proposed Method Combining the RL Agent and Augmented GA Showed Better Performance in Terms of Solution Quality and Time Cost. overall, in All the Cases Tested, the Proposed Method Showed Better Performance Than the Augmented GA Without RL

Practical Fixture Design for Passive Intermodulation Tests for Flexible Metallic Contacts

Passive intermodulation (PIM) commonly exists in non-ideal metallic contacts. Since PIM typically represents an extremely low level of nonlinearity, it has not drawn enough attention over the years except for extremely high-power applications such as base stations. However, in recent years, the study on PIM has become essential in universally used consumer electronics design because of the higher requirement on the radio frequency (RF) sensitivity of wireless communications. The metal contacts caused PIM can create the sideband spectrum to interfere with the receiving band in the frequency divide duplex (FDD) mode. Therefore, the study on PIM for the frequently used flexible metallic components is important in the industry. The PIM characterizations for the flexible components at least demand the compression variability and the capability to inject high-power signals while monitoring the sideband spectrum. It is preferred to have the access to measuring more relevant quantities. This paper aims to summarize the practical experience in designing a high-dynamic range and multi-purpose applicable test setup for characterizing PIM in the flexible components. Capabilities to precisely measure/control PIM, gap variability, tilted angle variability, and DC resistance (DCR) are presented with measurement examples

Static I-V based PIM Evaluation for Spring and Fabric-Over-Foam Contacts

Spring Clips and Fabric-Over-Foams (FOFs) Are Widely Used in Mobile Devices for Electrical Connection Purposes. However, the Imperfect Metallic Connections Tend to Induce Passive Intermodulation (PIM), Resulting in a Receiver Sensitivity Degradation, Known as RP Desensitization. Due to the Complexity of the PIM Characterization, there is Not Yet a Way to Evaluate PIM Performance using a Simple Setup for Environments Like Factories. in This Paper, a Current-Voltage (I-V) Behavior-Based PIM Evaluation Method is Proposed and Validated with Various Metallic Contacts and Contact Forces. the Test Results Demonstrated the Feasibility of the PIM Performance Evaluation based on the Measured Static I-V Curve