Abstract: Essentially, the shared-frequency jamming between shipborne radars is of an electromagnetic compatibility within the warship formation. The shared-frequency jamming must be cancelled to ensure the shipborne radars of the warship formation operate cooperatively. A general method for canceling the shared-frequency jamming is described firstly. For incoherent radars, a device against shared-frequency jamming is developed, which increases the PRF, changes the shared-frequency jamming into asynchronous jamming, and then cancels the jamming by using the anti-asynchronous signal processing method. Experiments on the sea show that this method can effectively cancel the shared-frequency jamming between same types of shipborne radars for the warship formation.