Apparatus and method for improving antenna sidelobe cancellation

摘要

An apparatus and method for use in an n-element electronically scannable array antenna provides a notched auxillary radiation pattern for use in reducing interference energy received in the sidelobes of the antenna's main radiation pattern. The apparatus includes circuitry for feeding the antenna elements in series from one end of the array to the opposed end thereof. Each antenna element is fed through a directional coupler which is responsive to its associated antenna element along with the downstream antenna elements in the array. The directional couplers provide a first output signal for forming a primary radiation pattern. At least one directional coupler also provides a second output signal on receive for forming an auxiliary radiation pattern having a notch in the direction of the primary radiation pattern main beam and electronically steerable therewith, and a relatively uniform response in all other directions. The first and second outputs may be fed to a combining circuit for cancelling or blanking the signal appearing in the sidelobes of the primary radiation pattern.