A new simple method is described for synthesizing low-sidelobe sum and difference patterns with partially adaptive weights. By partially adaptive, we mean that only part of the weights are adapted for simultaneous nulling. These adaptive weights arc shared by the sum and difference channels, leading to a significant reduction in the number of variable attenuators/phase shifters used, as compared to the fully adaptive implementation. An objective function is derived that yields different configurations of the shared adaptive weights. Numerical examples are presented to ascertain the efficacy of the new method for both point and extended interference.