Abstract: A method of nulling out interference sources in a large-aperture phased ay radar system is described. The system has apriori knowledge of the interference sources and depends upon access to the array element phase shifters for injection of phase only or phase and amplitude perturbations, of a mainbeam aperture distribution, into said array element phase shifters. The phase or phase and amplitude perturbations are derived from an aperture ripple modulation algorithm. The system does not require any auxiliary elements or correlators or beamformers.A method of nulling out interference sources in a monopulse large-aperture phased array radar system is also described wherein the phase only or phase and amplitude perturbations are injected into both the sum and difference beams.

Abstract: A phased array lens antenna which includes a lens having two faces disposed ubstantially at a right angle to each other. Transmit-receive modules which include phase-shifters are shared between the two lens faces. Two lens antennas positioned in back-to-back relationship about a ship superstructure scan 360.degree..

Abstract: The architecture of this invention makes multiple use of switched time-delay circuits to reduce the complexity of both series and parallel feed antenna arrays. Each time-delay circuit can give a delay that can be switched to values between 0 and 2d/c, where d is the inter-element spacing and c is the velocity of light. At the highest frequency of the series feed array, the elements are spaced by .lambda./2 to avoid grating lobes and the maximum delay corresponds to 360.degree. of phaseshift. When the time-delays are set half way (d/c), the various lines feeding the elements of the array at the aperture have bias delays that make them all equal in length, thereby giving a broadside beam, independent of frequency. At the highest frequency, the switchable time delay gives some excess in available delay. If additional excess time-delay is needed it can be obtained by increasing the time delay circuit range. Insertion loss is proportional to the number of bits used.