Abstract: An equalizer employed with a receiver for cancelling an interfering signal due to low cross-polarization isolation. The present equalizer provides a simple and inexpensive cross-polarization interference cancellation system. The equalizer uses an error signal generated in a residual carrier detector to determine the magnitude of an interfering signal and inputs a cancelling signal to the co-polarized channel until power in the error signal is minimized. In the equalizer, the determination of the magnitude of the interfering signal is performed at baseband (after demodulation but prior to data detection) and the cancellation is performed at RF, prior to dispersive microwave elements. In the receiver, co- and cross-polarized signals are received and amplified. A copy of the cross channel input signal is supplied to each receiver channel. An RF vector modulator is used to control the phase and amplitude of the cross-polarized signal prior to summation with a desired co-polarized signal.