Evaluation method of balance mismatch using CMRR measurement for printed circuit board

When a primary factor of common-mode noise is corresponding to mismatch of balance on the wiring, the balance degree may be obtained from CMRR (Common Mode Rejection Ratio) of the printed circuit board in the equipment. We calculated CDF(Current Division Factors) as balance degree of micro strip lines. And we showed relational expression of the balance degree and CMRR. By the CMRR measurement, the mismatch of balance between cable and substrate wiring can be evaluated quantitatively.