An electrical connector includes a housing having a terminating side and a front side that is configured to mate with a mating connector. The electrical connector also includes signal and ground conductors extending through the housing. The signal and ground conductors are configured to engage the mating connector. The signal conductors form a plurality of signal pairs configured to carry differential signals. The ground conductors are interleaved between the signal pairs. The electrical connector further has at least one resonance-control ground bus that includes a ground frame and a support body. The support body at least partially covers the ground frame. The support body comprises a lossy material. The ground frame includes multiple arms that each engage and electrically connect to a respective one of the ground conductors in order to electrically common the ground conductors that are engaged by the arms.