I/O Coupling EMI Calculator

High frequency signals can couple to I/O nets that carry the coupled energy away from the board. The common-mode currents induced on cables attached to I/O nets can result in significant radiated emissions. A closed-form expression was developed to estimate the maximum radiated emissions in [1]. The algorithm employed to make the calculations below is described in [2].


Top View

Side View
top viewside view
Board
Length (L) =  mmWidth (W) =  mm
Dielectric constant (εr) =

Traces
Width (a) =  mmDistance (s) =  mm
Height (t) =  mm
Coupling length (lcoupling) =  mm
I/O line length (ltrace) =  mm
Circuit Terminations
RL=  OhmRNE=  Ohm

Voltage Source

Amplitude A): V
Lower frequency (f0): MHz
Upper frequency (f1): MHz


[1] C. Su and T. Hubing, "Calculating Radiated Emissions due to I/O Line Coupling on Printed Circuit Boards using the Imbalance Difference Method," IEEE Trans. on Electromagnetic Compatibility, vol. 54, no. 1, Feb. 2012, pp. 212-217.

[2] C. Zhu and T. Hubing, "Maximum Radiated Emission Calculator: I/O Coupling Algorithm," CVEL-13-045, Aug. 24, 2013.

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