A wide band frequency domain canceller is used in cosite mitigation interference in which a signal tapped from a transmit antenna is coupled to a Chirp Fourier Transform to covert the signal into the frequency domain. The frequency domain signal is vector multiplied with a path transform function to add the path transfer function values to the sampled signal, after which the processed frequency domain signal is converted back into the time domain by an Inverse Chirp Fourier Transform, after which it is inverted and coupled into the receive path of a cosited receiver.