A self-steering phased antenna array repeater system in which signals from a distant source at two spaced receptors are relatively shifted in phase and combined in a square law mixer. The output mixer current is a function of their phase difference and indicates the direction in which the signals arrive. This current is used to bring the phase of received signals together for combining and to introduce the same phase difference but of opposite sign for re-radiation by applying the current as the control for at least one injection locked oscillator which produces a phase shift according to the same function as the mixer output.
