Broadside coupled pair On core On prepreg www

Broadside coupled pair. On core / On prepreg ? www. polarinstruments. com

Broadside Coupled Pair - On Core? - On Preg? In the current version of Si 8000 m impedance field solver we show broadside coupled pairs modeled only on the two sides of a core. This is the preferred construction as registration of the line pair is optimised. However… In the event that the pair are modeled on the two sides of prepreg, it becomes necessary to adjust the H 1 and H 2 dimensions to take into account the fact that they no longer directly correspond to the thickness of the dielectric material layers. This shortcoming will be addressed in a future version of Si 8000 but until that time the drawings on the following pages illustrate how the H 1 and H 2 dimensions must be constructed from the dielectric and copper dimensions. The three pictures that follow “are worth a thousand words. ”

Broadside Coupled Pair H 2 W 2 T 1 H 1 W 1 T 1 H 2 W 2

Broadside Coupled Pair on Core H 2 H 1 W 2 Preg Er 2 W 1 Core Er 1 T 1 H 2 W 2 Preg Er 2

Broadside Coupled Pair on Preg H 2 H 1 W 2 W 1 Core Er 2 T 1 Preg Er 1 T 1 H 2 W 2 Core Er 2 We “trick” the current structure into giving a close approximation of impedance. H 1 = overall prepreg thickness – (2 x T 1) and H 2 = core thickness + T 1. We ignore the small error caused by the dielectric interface being in the wrong position for the field solver (the solver thinks it is at the H 1 & H 2 interface. )

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