Measurement of differential mode propagation in printed circuit board for satellites applications (original) (raw)
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IEEE International Symposium on Electromagnetic Compatibility. Symposium Record (Cat. No.00CH37016), 2000
Experimental measurements and numerical modeling were used to study the EM1 performance of a module-on-backplane connector for various configurations of signal-return pin-outs. A commercially available open-pinfield connector was used in these results to connect between the mother-board and the daughter-card. The experimental techniques, based on measuring I&J, included both commonmode current measurements and monopole near-field probe measurements. The FDTD method was used to provide numerical support of the near-field measurements and generally agreed with the measured results for frequencies up to 3 GHz. The FDTD method was also used to investigate the relationship between the radiated EM1 at 3 m and the connector pin-out configurations.
2003
This paper provides an experimental verification of analytical expressions for predicting radiated electromagnetic fields from straight interconnect cables carrying high-frequency currents. These analytical expressions are derived through two different models. The former model is based on the assumption that a radiating two-wire transmission line can be considered as two Hertzian dipoles, while in the latter one each radiating wire is treated as a chain of short radiating dipoles. The radiated field is calculated and measured at selected locations and the results are compared in order to verify the agreement among them. Different configurations (two parallel cables at various distances from a conducting ground plane) are considered.
2010 IEEE International Symposium on Electromagnetic Compatibility, 2010
This paper investigates the impact of return path discontinuities on both signal and power integrity of high speed interconnects. A test board is built for the purpose and 4 different configurations are analyzed and correlation between measurements and simulations (coming from a full wave 3D EM field simulator) results is also presented. Both time and frequency domain results are analyzed and design guidelines are provided. It is observed that return path discontinuities have a sensible impact on ground bounce in single-ended signals; however the differential signaling can drastically reduces it. Discontinuities from gaps in return paths (e.g. plane splits) and connectors impact the differential signals on both insertion loss and cross talk. The real value of return/grounding vias is to reduce the common signal noise.
On the Electromagnetic Radiation of Printed-Circuit-Board Interconnections
IEEE Transactions on Electromagnetic Compatibility, 2005
Large ground and supply layers on interconnected boards represent a radiating antenna structure which may be efficiently excited at its resonances by small high-frequency potential differences. Such potential differences between the boards mainly originate from the inevitable inductive impedance of the signal-current return path in the connector, usually provided by ground pins. The presented modeling approach is based on an antenna transfer function for the global interconnecting structure and a partial-inductance equivalent circuit for the connector. As shown by the example of a motherboard-daughterboard structure, the model enables a systematic study of the radiation mechanism, depending on signal/ground-pin configuration, as well as geometrical and electrical parameters. In conjunction with SPICE simulations of the connector equivalent circuit, the signal driver and receiver dynamic characteristic can also be properly included. Validation is provided by full-wave simulation and measurement results.
2018 2nd URSI Atlantic Radio Science Meeting (AT-RASC), 2018
This proposal deals with the assessment of the statistical risk of underestimating conducted electromagnetic levels in the framework of electromagnetic compatibility (EMC) testing for "in-flight" satellites' configurations. In the following, the context of this study is briefly described. Then, the theoretical foundations are presented including: deterministic models for grounding and bonding networks, and the framework for uncertainty propagation. Indeed, noticeable differences exist between "test" and "in-flight" configurations that may lead to overestimating and/or underestimating EMC confidence margins. In this context, a particular focus is given for Monte Carlo (MC) and Stochastic Collocation (SC) methods: the use of the two techniques is illustrated through Multi-conductor Transmission Line (MTL) simulations. The MTL method allows taking into account "uncertain" grounding of an equivalent MTL system including screening and straps bonding. A final discussion is proposed with EMC recommendations.
Investigation on EM radiations from interconnects in integrated circuits
TELKOMNIKA Telecommunication Computing Electronics and Control, 2020
Characterization and estimation of interconnections behavior in integrated circuits design before the implementation phase is of paramount importance. This behavior seen as microstrip antennas gets complex as the internal signal (square or sine waves) frequencies increase. Thus, they become the preferred path for the propagation of electromagnetic disturbances. In this work we have worked out the numerical modeling of the electromagnetic interactions characterizing the electromagnetic compatibility in the microstrip transmission lines. The effect of these electromagnetic interactions in different structures topologies are studied through the analysis of the influence of the supply signals frequency and structures. The spacing between transmission line tracks and the number of tracks superposition is modeled. The evolution and variation of the scheme parameters in the frequency domain are determined. The transmission lines are considered parallel of equal spacing and superposed tracks of equal spacing and thickness. The capacitance and inductance matrices are computed and discussed. The results are found to comply with current research outcomes.
High-performance inter-PCB connectors: analysis of EMI characteristics
IEEE Transactions on Electromagnetic Compatibility, 2002
Electromagnetic interference (EMI) coupling associated with inter-board connection is investigated herein. Two experimental techniques, based on 21 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 agreement is achieved between the measurements and the FDTD modeled results. Index Terms-Common-mode current, finite-difference time domain (FDTD), inter-printed-circuit-board (inter-PCB) connector, near field, parameter.
IEEE Transactions on Electromagnetic Compatibility, 2011
This paper deals with the susceptibility of electronic units to radiated electromagnetic (EM) interference and specifically, it focuses on the parasitic coupling of EM fields with printed circuit board interconnects like microstrip lines. To this purpose, a uniform lossless microstrip line illuminated by an EM plane wave is considered and the voltages at the line terminations are evaluated referring to the Baum-Liu-Tesche equations. Based on this, a new algorithm to identify, frequency-by-frequency, the incidence angles and the polarization of the impinging field that gives rise to the maximum induced voltages at the line terminations is presented.
Investigation of split groundplanes at the connector for EMI control
IEEE 1997, EMC, Austin Style. IEEE 1997 International Symposium on Electromagnetic Compatibility. Symposium Record (Cat. No.97CH36113), 1997
EM1 can often be reduced by selectively filtering various parts of a given system. One common method employed by designers is to split the groundplane near the chassis and route 1/0 lines over the split. The rationale is based on providing a large series impedance to common-mode currents on the 1/0 lines. In this manner, PCB designers hope to lower the level of noise currents contributing to radiation. This work studies the efficacy of the groundplane split as a deterrent for EM1 associated with 1/0 lines being driven against other extended reference structures. A test-board was developed to analyze the impedance of the groundplane split with various configurations.
Evaluation of the propagation constants of differential PCB interconnections
2007 IEEE Workshop on Signal Propagation on Interconnects, 2007
Today the telecommunication equipments are characterized by transmission bandwidths of tents of GHz. Consequently the digital signals into play reach data rates of some Gbps with rise/fall times of few picoseconds. In this context it is important to correctly characterize the transmission lines on boards for studying the signal propagation as a function of the frequency. The more effective technique starts from measurements, connecting the studied traces to the measurement instruments by means of transition networks or fixtures. But in this case the connective errors due to the connector mismatches and discontinuities have to be removed. The paper proposes different mathematical deembedding procedures to evaluate the propagation constant of differential traces, de-embedded by the effects of the SMA's connecting them to the VNA.