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Full-Text Articles in Engineering
Dc Power-Bus Noise Isolation With Power-Plane Segmentation, Wei Cui, Jun Fan, Yong Ren, Hao Shi, James L. Drewniak, Richard E. Dubroff
Dc Power-Bus Noise Isolation With Power-Plane Segmentation, Wei Cui, Jun Fan, Yong Ren, Hao Shi, James L. Drewniak, Richard E. Dubroff
Electrical and Computer Engineering Faculty Research & Creative Works
Power-plane segmentation is often used for DC power-bus noise isolation in multilayer printed circuit board (PCB) designs. To achieve a desirable noise isolation, different power-plane segmentations can be used. A suitable modeling approach, as well as measurements, were employed in this work to study the noise isolation with several power-plane segmentation designs. The geometries studied include power islands, and totally segmented power planes. The effects of the power-bus noise isolation with different types of power island connections, locations of segmentation, and shapes were analyzed, and compared. The modeled and measured results show that suitable power-plane segmentation can result in significant …
A Study On Influence Of Guard Band On Common-Mode Current Related To A Microstrip Line, Yoshiki Kayano, Motoshi Tanaka, James L. Drewniak, Hiroshi Inoue
A Study On Influence Of Guard Band On Common-Mode Current Related To A Microstrip Line, Yoshiki Kayano, Motoshi Tanaka, James L. Drewniak, Hiroshi Inoue
Electrical and Computer Engineering Faculty Research & Creative Works
Influence of guard band on common-mode (CM) current related to a microstrip line (trace) has been studied experimental and FDTD simulation. As the guard band, copper tape is connected along the entire edge of the ground plane. It is cleared that a guard band parallel to and near a trace is most effective in suppressing the CM current. An empirical formula to quantify the relationship between the position of a trace and CM current of the case with a guard band is proposed. Calculated results using the empirical formula and FDTD modeling are in good agreement, which indicates this empirical …
Printed Circuit Board Emi Source Mechanisms, Todd H. Hubing
Printed Circuit Board Emi Source Mechanisms, Todd H. Hubing
Electrical and Computer Engineering Faculty Research & Creative Works
This tutorial paper reviews the basic mechanisms by which signal voltages and currents on a printed circuit board produce unintentional radiated emissions.
Multilevel Inverter-Based Dual-Frequency Power Supply, B. Diong, Keith Corzine, S. Basireddy, Shuai Lu
Multilevel Inverter-Based Dual-Frequency Power Supply, B. Diong, Keith Corzine, S. Basireddy, Shuai Lu
Electrical and Computer Engineering Faculty Research & Creative Works
Most existing power supplies for induction heating equipment produce voltage at a single (adjustable) frequency. Recently, however, induction heating power supplies that produce voltage at two (adjustable) frequencies simultaneously have been introduced and commercialized. These represent a significant development particularly for heat-treating workpieces with uneven geometries, such as gears. Still, the existing approaches to dual-frequency voltage generation could be improved upon to achieve better control, higher efficiency, and reduced electromagnetic interference. This letter proposes the use of multilevel inverters for providing power at two frequencies simultaneously. It describes how the stepping angles for the desired output from such inverters can …
Estimating Dc Power Bus Noise, Jingkun Mao, Bruce Archambeault, James L. Drewniak, Thomas Van Doren
Estimating Dc Power Bus Noise, Jingkun Mao, Bruce Archambeault, James L. Drewniak, Thomas Van Doren
Electrical and Computer Engineering Faculty Research & Creative Works
Simultaneous switching noise (SSN) resulting from IC devices can result in significant power bus noise, as well as radiation problems. An approach for estimating the power bus noise spectrum is presented in this paper. The power bus noise caused by digital circuits injecting high-frequency noise onto the DC buses feeding digital devices is calculated. The transient current drawn by an IC device is modeled using the load current and the shoot-through current through the power dissipation capacitance. Modeling and experimental results for several digital chips are shown. The modeling agrees well with the experimental results.
Modeling Noise Coupling From Non-Parallel Pcb Trace Routing, Shaofeng Luan, Fengchao Xiao, W. Liu, Jun Fan, Yoshio Kami, James L. Drewniak, Richard E. Dubroff
Modeling Noise Coupling From Non-Parallel Pcb Trace Routing, Shaofeng Luan, Fengchao Xiao, W. Liu, Jun Fan, Yoshio Kami, James L. Drewniak, Richard E. Dubroff
Electrical and Computer Engineering Faculty Research & Creative Works
Coupling between PCB signal traces in proximity is of concern to PCB designers and EMC engineers. The behavior of noise coupling between non-parallel microstrip lines is studied in this paper by a full-wave numerical modeling method CEMPIE, designating a circuit extraction approach based on a mixed-potential integral equation formulation. Good agreement between the numerical results and measurements was obtained.
External Parasitic Inductance In Microstrip And Stripline Geometries Of Finite Size, Marina Koledintseva, James L. Drewniak, Thomas Van Doren, David M. Hockanson
External Parasitic Inductance In Microstrip And Stripline Geometries Of Finite Size, Marina Koledintseva, James L. Drewniak, Thomas Van Doren, David M. Hockanson
Electrical and Computer Engineering Faculty Research & Creative Works
An external parasitic ground (return) plane inductance, or a mutual inductance associated with fringing magnetic fields in planar transmission line structures, is the culprit of common-mode voltage (ground plane noise) that leads to parasitic radiation of the corresponding unintentional "antennas" in high-speed electronic equipment. Mutual inductance of this sort in microstrip and stripline structures is studied here using an analytical quasi- magnetostatic approach and FDTD modeling. Closed-form expressions for mutual inductance in symmetrical and asymmetrical microstrip and stripline structures are presented.
Anticipating Full Vehicle Radiated Emi From Module-Level Testing In Automobiles, Geping Liu, Chingchi Chen, Yuhua Tu, James L. Drewniak
Anticipating Full Vehicle Radiated Emi From Module-Level Testing In Automobiles, Geping Liu, Chingchi Chen, Yuhua Tu, James L. Drewniak
Electrical and Computer Engineering Faculty Research & Creative Works
EMI due to common-mode currents on cables routed in automobiles was studied using a test device designed to mimic a vehicle. Both experimental work and Finite-Difference Time-Domain (FDTD) modeling were employed in this paper. The good agreement between the measurements and modeling results indicates that the numerical tools can be a useful aid in predicting vehicle-level EMI by developing vehicle transfer functions and measuring the module-level EMI characteristics on the bench top.
Field Extraction From Near Field Scanning For A Microstrip Structure, Lin Zhang, Kevin P. Slattery, Chen Wang, Masahiro Yamaguchi, K.-I. Arai, Richard E. Dubroff, James L. Drewniak, David Pommerenke, Todd H. Hubing
Field Extraction From Near Field Scanning For A Microstrip Structure, Lin Zhang, Kevin P. Slattery, Chen Wang, Masahiro Yamaguchi, K.-I. Arai, Richard E. Dubroff, James L. Drewniak, David Pommerenke, Todd H. Hubing
Electrical and Computer Engineering Faculty Research & Creative Works
Currents associated with high-speed digital devices have significant impacts on EMI problems in VLSI design and operation. In this paper, a simple transmission line model was implemented as an initial step to represent the EMI mechanisms associated with an IC package. Numerical modeling results were compared with near field scanning measurements and show that the magnetic field deduced from the measurements agrees well with the numerical predictions.
Estimating The Noise Mitigation Effect Of Local Decoupling In Printed Circuit Boards, Jun Fan, Wei Cui, James L. Drewniak, Thomas Van Doren, James L. Knighten
Estimating The Noise Mitigation Effect Of Local Decoupling In Printed Circuit Boards, Jun Fan, Wei Cui, James L. Drewniak, Thomas Van Doren, James L. Knighten
Electrical and Computer Engineering Faculty Research & Creative Works
Local decoupling, i.e., placing decoupling capacitors sufficiently close to device power/ground pins in order to decrease the impedance of power bus at frequencies higher than the series resonant frequency, has been studied using a modeling approach, a hybrid lumped/distributed circuit model established and an expression to quantify the benefits of power bus noise mitigation due to local decoupling developed. In this work, a test board with a local decoupling capacitor was studied and the noise mitigation effect due to the capacitor placed adjacent to an input test port was measured. Closed-form expressions for self and mutual inductances of vias are …
High-Performance Inter-Pcb Connectors: Analysis Of Emi Characteristics, Xiaoning Ye, James L. Drewniak, Jim Nadolny, David M. Hockanson
High-Performance Inter-Pcb Connectors: Analysis Of Emi Characteristics, Xiaoning Ye, James L. Drewniak, Jim Nadolny, David M. Hockanson
Electrical and Computer Engineering Faculty Research & Creative Works
Electromagnetic interference (EMI) coupling associated with inter-board connection is investigated. Two experimental techniques, based on |S21| measurements, including both common-mode current and near-field measurements, are reported. Both methods, as well as finite difference time domain (FDTD) modeling, were used as experimental and numerical tools for inter-printed-circuit-board (inter-PCB) connector evaluation. The EMI performance of a lab-constructed stacked-card connector, and a commercially available module-on-backplane connector were studied. EMI characteristics of the connectors are demonstrated by investigating a few aspects of the design: type of shield/ground blade for signal return, number and length of ground pins, signal pin designation, etc. Good …
Fdtd Modeling Incorporating A Two-Port Network For I/O Line Emi Filtering Design, Xiaoning Ye, James L. Drewniak
Fdtd Modeling Incorporating A Two-Port Network For I/O Line Emi Filtering Design, Xiaoning Ye, James L. Drewniak
Electrical and Computer Engineering Faculty Research & Creative Works
Electromagnetic interference (EMI) filters are often utilized on I/O lines to reduce high-frequency noise form being conducted off the printed circuit board (PCB) and causing EMI problems. The filtering performance is often compromised at high frequencies due to parasitics associated with the filter itself, or the PCB layout and interconnects. Finite difference time domain (FDTD) modeling can be used to quantify the effect of PCB layout and interconnects, as well as filter type, on the EMI performance of I/O line filtering. FDTD modeling of a T-type and π-type filter consisting of surface-mount ferrites and capacitors is considered herein. The FDTD …
An Expert System Architecture To Detect System-Level Automotive Emc Problems, Sreeniwas Ranganathan, Daryl G. Beetner, R. Wiese, Todd H. Hubing
An Expert System Architecture To Detect System-Level Automotive Emc Problems, Sreeniwas Ranganathan, Daryl G. Beetner, R. Wiese, Todd H. Hubing
Electrical and Computer Engineering Faculty Research & Creative Works
Improving EMC in automobiles requires methods to detect potential problems early in the design process. Issues involved in the development of a system-level automotive EMC expert system are explored. The proposed system would help identify problems with radiation and immunity, crosstalk, placement of modules, component grounding and EMC testing. The architecture of the expert system has been developed. The system architecture is designed to allow rapid analysis of automobile designs, to point out potential problems and to suggest possible solutions.
Reducing Power Bus Impedance At Resonance With Lossy Components, Todd H. Hubing, Theodore M. Zeeff
Reducing Power Bus Impedance At Resonance With Lossy Components, Todd H. Hubing, Theodore M. Zeeff
Electrical and Computer Engineering Faculty Research & Creative Works
Power bus structures in printed circuit boards with solid power and ground planes exhibit resonances. When the power bus is resonant, the power bus impedance can increase dramatically. This paper explores the effect of component equivalent series resistance (ESR) on power bus resonances. General guidelines for selecting an optimum ESR are provided and are supported by laboratory measurements and numerical simulations.
Emi Mitigation With Multilayer Power-Bus Stacks And Via Stitching Of Reference Planes, Xiaoning Ye, David M. Hockanson, Min Li, Yong Ren, Wei Cui, James L. Drewniak, Richard E. Dubroff
Emi Mitigation With Multilayer Power-Bus Stacks And Via Stitching Of Reference Planes, Xiaoning Ye, David M. Hockanson, Min Li, Yong Ren, Wei Cui, James L. Drewniak, Richard E. Dubroff
Electrical and Computer Engineering Faculty Research & Creative Works
General methods for reducing printed circuit board (PCB) emissions over a broad band of high frequencies are necessary to meet EMI requirements, as processors become faster and more powerful. One mechanism by which EMI can be coupled off a PCB or multichip module (MCM) structure is from high-frequency fringing electric fields on the dc power and reference planes at the substrate periphery An approach for EMI mitigation by stitching multiple ground planes together along the periphery of multilayer PCB power-bus stacks with closely spaced vias is reported and quantified in this paper. Power-bus noise induced EMI and coupling from the …
Quantifying Smt Decoupling Capacitor Placement In Dc Power-Bus Design For Multilayer Pcbs, Jun Fan, James L. Drewniak, James L. Knighten, Norman W. Smith, Antonio Orlandi, Thomas Van Doren, Todd H. Hubing, Richard E. Dubroff
Quantifying Smt Decoupling Capacitor Placement In Dc Power-Bus Design For Multilayer Pcbs, Jun Fan, James L. Drewniak, James L. Knighten, Norman W. Smith, Antonio Orlandi, Thomas Van Doren, Todd H. Hubing, Richard E. Dubroff
Electrical and Computer Engineering Faculty Research & Creative Works
Noise on a dc power-bus that results from device switching, as well as other potential mechanisms, is a primary source of many signal integrity (SI) and electromagnetic interference (EMI) problems. Surface mount technology (SMT) decoupling capacitors are commonly used to mitigate this power-bus noise. A critical design issue associated with this common practice in high-speed digital designs is placement of the capacitors with respect to the integrated circuits (ICs). Local decoupling, namely, placing SMT capacitors in proximity to ICs, is investigated in this study. Multilayer PCB designs that employ entire layers or area fills for power and ground in a …
Dc Power Bus Noise Isolation With Power Islands, Wei Cui, Jun Fan, Hao Shi, James L. Drewniak
Dc Power Bus Noise Isolation With Power Islands, Wei Cui, Jun Fan, Hao Shi, James L. Drewniak
Electrical and Computer Engineering Faculty Research & Creative Works
Segmented power planes are often used for DC power bus noise isolation in multi-layered printed circuit board (PCB) designs. To achieve a desirable noise isolation, different power plane segmentations can be used. A suitable modeling approach, as well as measurements, were employed to study the power bus isolation with several power plane segmentation configurations. The studied geometries included power island designs connected with a conducting bridge, a ferrite bead, and a π-filter. In addition, different conducting bridge widths and power island gap widths were analyzed, and compared. The modeled and measured results show that power plane segmentations with proper designs …
An Emi Estimate For Shielding-Enclosure Evaluation, Min Li, James L. Drewniak, S. Radu, Joe Nuebel, Todd H. Hubing, Richard E. Dubroff, Thomas Van Doren
An Emi Estimate For Shielding-Enclosure Evaluation, Min Li, James L. Drewniak, S. Radu, Joe Nuebel, Todd H. Hubing, Richard E. Dubroff, Thomas Van Doren
Electrical and Computer Engineering Faculty Research & Creative Works
A relatively simple, closed-form expression has been developed to estimate the EMI from shielding enclosures due to coupling from interior sources through slots and apertures at the enclosure cavity modes. A power-balance method, Bethe's (1944) small-hole theory, and empirically developed formulas for the relation between radiation, and slot length and number of slots, were employed to estimate an upper bound on the radiated EMI from shielding enclosures. Comparisons between measurements and estimated field strengths suitably agree within engineering accuracy.
Differential Signalling In Pcbs: Modeling And Validation Of Dielectric Losses And Effects Of Discontinuities, R. Araneo, Chen Wang, Xiaoxiong Gu, S. Celozzi, James L. Drewniak
Differential Signalling In Pcbs: Modeling And Validation Of Dielectric Losses And Effects Of Discontinuities, R. Araneo, Chen Wang, Xiaoxiong Gu, S. Celozzi, James L. Drewniak
Electrical and Computer Engineering Faculty Research & Creative Works
This paper focuses on differential signal transmission above ground planes with gaps, taking into account the dielectric and conductive losses of the substrate. An equivalent lumped-circuit is proposed and its suitability is investigated by comparing the obtained numerical results with the measured data. Furthermore the differential to common mode conversion of the waves, while crossing the gap, is theoretically analyzed and experimentally verified.
Emi Considerations In Selecting Heat-Sink-Thermal-Gasket Materials, Yu Huang, J. E. Butler, M. De Sorgo, Richard E. Dubroff, Todd H. Hubing, James L. Drewniak, Thomas Van Doren
Emi Considerations In Selecting Heat-Sink-Thermal-Gasket Materials, Yu Huang, J. E. Butler, M. De Sorgo, Richard E. Dubroff, Todd H. Hubing, James L. Drewniak, Thomas Van Doren
Electrical and Computer Engineering Faculty Research & Creative Works
Specific design criteria are proposed to mitigate radiated emissions from a resonant enclosure excited by a heat sink acting as a microstrip patch antenna source. In this particular application, the EMI mechanism is assumed to be due to coupling from the dominant TMz010 mode to one or more resonant modes associated with the enclosure dimensions. The enclosure is then presumed to radiate, at the enclosure resonance frequencies, through one or more apertures, slots, or seams. The EMI-reduction strategy consists of shifting the resonant frequency of the dominant-patch antenna mode by dielectrically loading the patch antenna with thermal-gasket material …
Grounding Of Heatpipe/Heatspreader And Heatsink Structures For Emi Mitigation, Chen Wang, James L. Drewniak, D. Wang, Ray Alexander, James L. Knighten, David M. Hockanson
Grounding Of Heatpipe/Heatspreader And Heatsink Structures For Emi Mitigation, Chen Wang, James L. Drewniak, D. Wang, Ray Alexander, James L. Knighten, David M. Hockanson
Electrical and Computer Engineering Faculty Research & Creative Works
EMI problems caused by the presence of heatpipe/heatspreader and heatsink structures in a high-speed design are well known in engineering practice. High-frequency noise can be coupled from IC packages to an electrically conductive heatsink or heatspreader attached to the IC, which then is radiated, or the energy coupled to an enclosure cavity mode. This EMI coupling path was modeled with the finite-difference time-domain (FDTD) method, and a mitigation approach was investigated. Good agreement between measurements and FDTD modeling is demonstrated, indicating FDTD is a suitable tool for analysis and design. Then, several grounding schemes suitable for a heatsink or heatspreader …
Mitigating Power Bus Noise With Embedded Capacitance In Pcb Designs, Minjia Xu, Todd H. Hubing, Juan Chen, James L. Drewniak, Thomas Van Doren, Richard E. Dubroff
Mitigating Power Bus Noise With Embedded Capacitance In Pcb Designs, Minjia Xu, Todd H. Hubing, Juan Chen, James L. Drewniak, Thomas Van Doren, Richard E. Dubroff
Electrical and Computer Engineering Faculty Research & Creative Works
This paper investigates the power bus noise and power bus impedance of printed circuit boards with four different kinds of embedded capacitance. These boards have power-ground plane pairs separated by a very thin layer of material with high dielectric permittivity. It is shown that embedded capacitance effectively reduces power bus noise over the entire frequency range evaluated (up to 5 GHz).
Investigation Of Pcb Layout Parasitics In Emi Filtering Of I/O Lines, Xiaoning Ye, Geping Liu, James L. Drewniak
Investigation Of Pcb Layout Parasitics In Emi Filtering Of I/O Lines, Xiaoning Ye, Geping Liu, James L. Drewniak
Electrical and Computer Engineering Faculty Research & Creative Works
EMI filters are often utilized on I/O lines to reduce high-frequency noise from being conducted or coupled off the PCB and resulting in an EMI problem. However, layout parasitics are usually inevitable in practical circuit design, and the filtering performance may vary. In this study, the impact of the board layout on the filtering performance is investigated by |S21| measurements of sample PCB boards with different filter layouts. The finite-difference time-domain method is applied to model the boards, support the experimental work, and can be used to provide a means for conducting "what-if" engineering studies.
Applying The Method Of Moments And The Partial Element Equivalent Circuit Modeling Techniques To A Special Challenge Problem Of A Pc Board With Long Wires Attached, Yun Ji, Bruce Archambeault, Todd H. Hubing
Applying The Method Of Moments And The Partial Element Equivalent Circuit Modeling Techniques To A Special Challenge Problem Of A Pc Board With Long Wires Attached, Yun Ji, Bruce Archambeault, Todd H. Hubing
Electrical and Computer Engineering Faculty Research & Creative Works
This paper investigates a canonical printed circuit board (PCB) problem using both a method of moments (MoM) and a partial element equivalent circuit (PEEC) modeling technique. The problem consists of a PCB populated with three traces. One trace is a signal line and the other two are I/O lines that couple to the signal line and extend beyond the boundary of the board. Although the MoM code was a frequency domain code and the PEEC code was a time-domain code, good agreement was achieved in both the time-domain and the frequency-domain
20-H Rule Modeling And Measurements, Todd H. Hubing, Hwan-Woo Shim
20-H Rule Modeling And Measurements, Todd H. Hubing, Hwan-Woo Shim
Electrical and Computer Engineering Faculty Research & Creative Works
The 20-H rule is a printed circuit board layout guideline. On boards with power and ground planes, the fringing field at the edges of the board is contained by backing the edge of the power plane away from the edge of the board by a distance equal to 20 times the separation distance between the planes. In this study, test boards were built and measured with and without implementing the 20-H rule. The measured results are compared to numerical models. The results of this study show that, although the near fields are more contained, the radiation from a board implementing …
Estimation Of Printed Circuit Board Power Bus Noise At Resonance Using A Simple Transmission Line Model, H. Hu, Todd H. Hubing, Thomas Van Doren
Estimation Of Printed Circuit Board Power Bus Noise At Resonance Using A Simple Transmission Line Model, H. Hu, Todd H. Hubing, Thomas Van Doren
Electrical and Computer Engineering Faculty Research & Creative Works
The maximum coupling between printed circuit board components connected to the same power-ground plane pair often occurs at or near power bus resonances. Theoretically, the transfer coefficient, S 21 , between two locations on the power bus can be as high as 0dB (i.e. perfect coupling) near resonant frequencies. However, in practice the coupling is usually much less due to losses in the power bus structure. Determining exactly what the maximum coupling will be in a lossy power bus structure requires a numerical model or measurement. However, an estimation of the maximum coupling can be obtained by drawing an analogy …
Experimental And Numerical Study Of The Radiation From Microstrip Bends, H. Wang, Yun Ji, Todd H. Hubing, James L. Drewniak, Thomas Van Doren, Richard E. Dubroff
Experimental And Numerical Study Of The Radiation From Microstrip Bends, H. Wang, Yun Ji, Todd H. Hubing, James L. Drewniak, Thomas Van Doren, Richard E. Dubroff
Electrical and Computer Engineering Faculty Research & Creative Works
This paper investigates the radiation from microstrip lines with 90-degree bends. A 1-GHz TEM cell is used to measure the radiation from microstrip lines with different kinds of bends. A full wave hybrid FEM/MoM code is used to compute the radiation. Both experimental and numerical results show that there is no significant difference between the radiation from right angle bends and bends with two 45-degree corners at frequencies and trace dimensions that are likely to be found on printed circuit boards.
Emi From Airflow Aperture Arrays In Shielding Enclosures-Experiments, Fdtd, And Mom Modeling, Min Li, Joe Nuebel, James L. Drewniak, Richard E. Dubroff, Todd H. Hubing, Thomas Van Doren
Emi From Airflow Aperture Arrays In Shielding Enclosures-Experiments, Fdtd, And Mom Modeling, Min Li, Joe Nuebel, James L. Drewniak, Richard E. Dubroff, Todd H. Hubing, Thomas Van Doren
Electrical and Computer Engineering Faculty Research & Creative Works
Aperture arrays designed to provide airflow through shielding enclosures can provide part of the coupling path from interior sources to external electromagnetic interference (EMI). In this work, radiation through aperture arrays is investigated numerically and experimentally. FDTD modeling is compared with measurements on aperture arrays in a test enclosure. The method of moments (MoM) is also utilized to study radiation from apertures and to investigate the mutual coupling between apertures in an infinite conducting plane. A simple design equation for the relation between aperture size and number and shielding effectiveness is proposed.
Fdtd And Fem/Mom Modeling Of Emi Resulting From A Trace Near A Pcb Edge, Daniel P. Berg, Motoshi Tanaka, Yun Ji, Xiaoning Ye, James L. Drewniak, Todd H. Hubing, Richard E. Dubroff, Thomas Van Doren
Fdtd And Fem/Mom Modeling Of Emi Resulting From A Trace Near A Pcb Edge, Daniel P. Berg, Motoshi Tanaka, Yun Ji, Xiaoning Ye, James L. Drewniak, Todd H. Hubing, Richard E. Dubroff, Thomas Van Doren
Electrical and Computer Engineering Faculty Research & Creative Works
PCB traces routed near board edges and carrying high-speed signals are considered to contribute to EMI problems. Consequently, design maxims state that traces that might have intentional or unintentional high frequency components on them be kept away from board edges. This costs valuable surface area as boards become more densely designed. Further, design maxims concerning traces near board edges are not well quantified. The increase in EMI as a trace is routed increasingly closer to the PCB edge has been studied experimentally and with numerical modeling.
Finite Element Modeling Of Patch Antenna And Cavity Sources, Yun Ji, Todd H. Hubing, James L. Drewniak
Finite Element Modeling Of Patch Antenna And Cavity Sources, Yun Ji, Todd H. Hubing, James L. Drewniak
Electrical and Computer Engineering Faculty Research & Creative Works
This paper examines two different approaches that can be used to model patch antennas and cavities fed by a coaxial cable. The probe model represents the feed as a current filament along the center conductor of the coaxial cable. The coaxial-cable model enforces the analytical field distribution at the cable opening. These two models have been implemented in a hybrid FEM/MoM code. A power bus structure and a cavity geometry with coaxial-cable feeds are investigated. Numerical results obtained for these two examples are compared with measurements. It is shown that the probe model should only be applied to electrically short …