The effect of various skew compensation strategies on mode conversion and radiation from high-speed connectors

Different skew compensation techniques for a high-speed connector are presented and mode conversion and radiation from these configurations are discussed. Although the mode conversion |S_cd12| from the proposed designs is improved about 10 dB as compared to the connector without any skew compensation strategies, the radiated power is not significantly reduced. According to the investigation of the current distribution, it shows that the radiated emission is strongly related to the antenna-mode current, instead of the common-mode current. Therefore, the reduced mode conversion from differential-mode signal to common-mode signal does not translate into suppression of the radiated emissions. Finally, the predicted radiation from the S-parameter formula in this work is examined. This formula is only valid for the lossless circuit board and it cannot be applied to the case of a lossy circuit board without de-embedding the effects of the PCB first.