1,720,981 research outputs found
Equivalent circuit models for the analysis of coaxial cables immunity
No full textThe paper deals with the development of equivalent circuit models of shielded cables suitable to analyze immunity by commercial circuit simulators. Equivalent circuits of coaxial cables based on different assumptions are proposed and validated by comparing the solutions with those derived by other approaches. Different circuit models are derived for the case of lossless and lossy cables
Numerical Prediction by MWS of Conducted and Radiated Disturbances on Circuits and Cables Produced by an ESD Event
No full textThe aim of this paper is to investigate conducted and radiated effects produced by a commercial electrostatic discharge (ESD) generator into circuits by using a commercial numerical code such as Microwave Studio (MWS) based on the finite integration technique. The ESD generator is efficiently modeled by the software tool, and the contact-mode discharge current is well reproduced taking into account the loading effect of the generator. The numerical models are validated by experimental results
Circuital and numerical modeling od ESD coupling to shielded cables
No full textThe discharge current in the contact mode and the voltage induced inside a shielded cable that interconnects two shielded enclosures are simulated following two approaches: the first is circuit-oriented and is derived by the transmission line theory, while the second is based on the numerical solution by using the Finite Integration Technique. The ESD generator is numerically modeled with conductive material, dielectric material and lumped circuital elements inside in order to reproduce the reference current discharge investigated by the working group in charge to prepare a new IEC 61000-4-2 standard. The numerical or circuital simulated current on the shield of the cable is then used to calculate the disturb on the loads of the cable by using a transmission line model that implements the transfer impedance concept. The proposed models are validated by comparison with measurements. Finally, different design choices are investigated
SPICE-like models for the analysis of the conducted and radiated immunity of shielded cables
No full textThe aim of this work is the development and validation of compact SPICE models suitable to analyze the conducted and radiated immunity of shielded cables. The reference structures are coaxial cables, and shielded cables with two parallel wires (i.e., twinax cable). The conducted and radiated immunity of the shielded cables are evaluated considering as source a known injected current on the cable shield, and the coupling with an external plane wave electromagnetic field, respectively. The circuit models are validated by comparing the results with those obtained by other approaches. The developed models are then used to quantify the main grounding practices of shielded cables. © 2004 IEEE
Two-wire shielded cable modeling for the analysis of conducted transient immunity
No full textAbstract— A SPICE model is proposed to simulate a typical boxto-box
structure when the interconnect is a two-wire shielded
cable. The goal is to carry out a very simple circuit that can be
easily implemented by any user interested in investigating
conducted transient immunity of a parallel-pair (twinax) or
twisted-pair shielded cable. The model is based on the classic
cable representation as a cascade of lumped element circuit cells
obtained considering the cable as a three-conductor transmission
line (TL) above a reference plane. Particular attention is here
addressed to properly define the mutual inductive coupling
between the wires and the shield in order to take into account the
penetration through apertures proper of real braided shields. The
model is suitable for direct transient analysis and allows modeling
any kind of cable terminations
New extraction procedure of shielded cable SPICE macro-model for the prediction of signal integrity and conducted immunity
No full textAn improved extraction procedure is here proposed to carry out shielded cable macro-model suitable to be implemented in any SPICE based circuit simulator. The proposed procedure permits to account frequency-dependent losses as skin effect, and frequency-dependent behaviour of the transfer impedance. The shielded cable is modelled by a four-port network with lumped time-constant parameters obtained by applying the proposed improved fitting technique. The proposed macro-model is validated by comparing the results with those obtained by measurements
SPICE Model Extraction for Signal Integrity Analysis of Unshielded Twisted Pairs from Full Wave Simulation
No full textImproved SPICE-like macromodels are
proposed to model unshielded twisted pairs (UTPs). The
equivalent SPICE circuits of UTPs cable are obtained by
applying suitable extraction techniques based on the Vector
Fitting procedure to the scattering matrix representation of
the cable. The proposed SPICE models are suitable to
analyze the transmission properties of UTPs taking into
account frequency-dependent losses, proximity effect, and
radiation losses. The characterization of the UTPs cable by
the scattering matrix is here performed by a three
dimensional full-wave numerical tool based on the Finite
Integration technique. The proposed extraction procedures
are absolutely general and can be also applied to measured
scattering parameters. The UTPs SPICE models are
validated by comparing the results with those provided by
the full-wave simulation and by measurements
A New Proposal for the Uncertainty Evaluation and Reduction in Air Electrostatic Discharge Tests
No full textThe technique used in air electrostatic discharge
(ESD) immunity tests to approach the generator tip to the
equipment under test is here dealt with. Specifically, the
uncertainty contribution associated to the measurement
technique is analyzed in depth. To this aim, a number of
simulations and experiments are carried out by means of a
proper test bed, which includes a purposely-developed slide
system. Through this system, the effects of different type A
uncertainty contributions are compared and the ESD
repeatability is assessed. Taking into account the type B
uncertainty contribution too, the purpose of the work is to
provide an original and efficient proposal for improving
the uncertainty evaluation in air ESD tests
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