A system and method corrects the phase of measurement signals obtained from remote heads during testing of a device. A first signal is transmitted along first and second transmission lines to respective remote heads. A shunt switch is connected between a remote end of the first transmission line and a first remote head, and another shunt switch is connected between a remote end of the second transmission line and a second remote head. The shunt switches in a first configuration respectively reflect the first signal back to a phase measurement apparatus as first and second reflected signals. The phase measurement apparatus determines a first reference phase and a second reference phase respectively based on the first and second reflected signals. A compensation unit compensates phase of the measurement signals based on the first and second reference phases.