A radar with a large number of antennas requires efficient design in its feeding network or transmit/receive modules (TRMs). We propose a method for simplifying the antenna system of a monopulse radar by attaching a single common weight to each antenna, both for sum and difference beams. A major novelty of our work lies in that the proposed technique can synthesize arbitrarily asymmetric monopulse beams with a common weight vector, using computationally efficient linear programming, not resorting to slow global optimization techniques. Therefore, common-weight monopulse beams can be produced in real time to reject ground clutter or null jamming signals