Simultaneous nulling in the sum and difference patterns of a monopulse antenna

Most adaptive array research neglects the problem of nulling in a monopulse antenna. Placing a null in the sum pattern does not automatically place a null in the difference pattern and vice versa. Nulls may be placed in the two patterns by having separate adaptive weights and controls for each channel, however, this method uses two sets of adaptive hardware for one antenna. This paper develops a technique for simultaneous nulling in the sum and difference patterns of a monopulse phased array using one set of adaptive weights shared by both channels. First, the technique is used for amplitude and phase nulling then for phase-only nulling. In each case, the ability to simultaneously null in both channels with one set of weights, chosen to place a null at a particular location, is theoretically demonstrated.