A connector has data signal conductors for communicating data signals and voltage reference (power and ground) conductors for the signals' return currents. Voltage reference conductors carrying the same voltage level are coupled together at one or more points between the ends of the connector to shift the connector's resonant frequency beyond an operating frequency range of the data signals. Decoupling capacitors may alternatively or additionally be inserted between pairs of voltage reference conductors carrying high and low voltage levels at one or more points between the ends of the connector to shift the connector's resonant frequency beyond an operating frequency range of the data signals.