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Skin Effect and Dielectric Loss Formulae

Skin effect loss in percent-signal-loss per inch of trace

Dielectric loss in percent-signal-loss per inch of trace

1 RSKIN(1GHz) f

2 Z0 1GHz

π f θ TD

Loss tangent

Trace delay per inch

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Skin Effect and Dielectric Loss Chart

107 108 109 1010

0.01

0.1

1

10

Stripline configuration(microstrip has a little less loss)

100-ohm differential pairs

Frequency (Hz)

Vertical signal loss (% per inch)

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Skin Effect and Dielectric Loss ExampleFiber Channel 1.06 Gb/s over 18” of FR-4

107 108 109 1010

0.01

0.1

1

10

Composite loss at max. data alt. rate of 530 MHz = 1% per inchLoss in 18 inches is 18%

For more accurate results use a 2-D field solver to computeskin loss and effective dielectricloss tangent

Frequency (Hz)

Vertical signal loss (% per inch)