Experimental Verification of Characteristic Mode Analysis (CMA) using Reverberation Chamber

In This Work, a Novel Experimental Validation of Characteristic Mode Analysis (CMA) is Proposed using Reverberation Chamber Measurements. using the Modal Weighting Coefficient Formulation based on the Magnetic Moment and Modal H Field Obtained from Solvers, the Total Radiated Power (TRP) is Calculated. This TRP is Compared with the TRP Obtained from the Reverberation Chamber Measurements. a Good Correlation between the Simulation and Measurement Was Achieved for a Simple Rectangular Plate of Size 15 Cm X 8 Cm with an Error of Less Than 4 DB

Predicting Radiated Emissions from an Electrical Drive System

A Measurement-Based SPICE Model is Proposed to Predict Radiated Emissions from an Electrical Drive System over a Frequency Range from 20-300 MHz. the Model Combines a Model for the Radiated Emissions from the Cabling and Housings with a Model for Coupling Inside the Electrical Motor. the Electromagnetic Properties of the Cabling and Housings Were Captured with Measured S-Parameters. the Coupling Mechanisms Inside the Electrical Machine Were Represented using a Circuit- Element based Model. the Intent is to Provide Insight into How Coupling Mechanisms and Placement of Structures in the Motor Affect Radiated Emissions from the Drive System, and to Give the Designer an Opportunity to Evaluate the Impact of Changes to the Motor Design. the Model Was Able to Predict Radiated Emissions within Several Decibels of the Measurement over the Frequency Range of Interest, to Provide Insight into Strategies for Fixing Emissions Issues, and to Provide Estimates for the Reduction in Emissions that Could Be Expected from Each Fix

Influence of Conformal Coatings on the Emc Performance of a Printed Circuit Board

Conformal coatings are often applied to printed circuit boards to protect the board and its components from environmental factors like moisture, chemicals, and vibration. The impact of a conformal coating on crosstalk and radiated emissions was studied in the following paper. Two coating materials were characterized in terms of their permittivity and permeability. The impact of the conformal coating was evaluated based on the crosstalk between microstrip traces, the radiated emissions from a switch-mode power supply (SMPS), and on coupling from an EMI filter to nearby components. The coatings increased crosstalk between microstrip traces by up to 5 ~ 6 dB, and increased radiated emissions from the SMPS by up to 8 dB. While the coating did not affect the performance of the EMI filter, a 5.5 dB increase in coupling was observed from the filter to nearby components. These effects should be considered if pre-compliance testing is performed before the coatings are applied

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

Backbone-base inclination as a fundamental determinant of nucleic acid self- and cross-pairing

The crystal structure of the duplex formed by oligo(2′,3′-dideoxy-β-d-glucopyranosyl)nucleotides (homo-DNA) revealed strongly inclined backbone and base-pair axes [Egli,M., Pallan,P.S., Pattanayek,R., Wilds,C.J., Lubini,P., Minasov,G., Dobler,M., Leumann,C.J. and Eschenmoser,A. (2006) Crystal structure of homo-DNA and nature's choice of pentose over hexose in the genetic system. J. Am. Chem. Soc., 128, 10847–10856]. This inclination is easily perceived because homo-DNA exhibits only a modest helical twist. Conversely, the tight coiling of strands conceals that the backbone-base inclinations for A- (DNA and RNA) and B-form (DNA) duplexes differ considerably. We have defined a parameter ηB that corresponds to the local inclination between sugar-phosphate backbone and base plane in nucleic acid strands. Here, we show its biological significance as a predictive measure for the relative strand polarities (antiparallel, aps, or parallel, ps) in duplexes of DNA, RNA and artificial nucleic acid pairing systems. The potential of formation of ps duplexes between complementary 16-mers with eight A and U(T) residues each was investigated with DNA, RNA, 2′-O-methylated RNA, homo-DNA and p-RNA, the ribopyranosyl isomer of RNA. The thermodynamic stabilities of the corresponding aps duplexes were also measured. As shown previously, DNA is capable of forming both ps and aps duplexes. However, all other tested systems are unable to form stable ps duplexes with reverse Watson–Crick (rWC) base pairs. This observation illustrates the handicap encountered by nucleic acid systems with inclinations ηB that differ significantly from 0° to form a ps rWC paired duplex. Accordingly, RNA with a backbone-base inclination of −30°, pairs strictly in an aps fashion. On the other hand, the more or less perpendicular orientation of backbone and bases in DNA allows it to adopt a ps rWC paired duplex. In addition to providing a rationalization of relative strand polarity with nucleic acids, the backbone-base inclination parameter is also a determinant of cross-pairing. Thus, systems with strongly deviating ηB angles will not pair with each other. Nucleic acid pairing systems with significant backbone-base inclinations can also be expected to display different stabilities depending on which terminus carries unpaired nucleotides. The negative inclination of RNA is consistent with the higher stability of duplexes with 3′- compared to those with 5′-dangling ends