A monopulse beam former for an array antenna composed of a plurality of sub-arrays. In one embodiment, a monopulse beam former includes, for each sub-array, a sum feed network and a delta feed network, each feeding an analog processor. The delta beam former includes a plurality of couplers with coupling coefficients increasing linearly across the sub-array. The analog processor includes a first gain-phase module in line with the output of the delta feed network, and a second gain-phase module adjusting the gain and phase of a portion of the output of the sum feed network added to the delta signal. The gain settings and phase settings of the first and second gain-phase modules are adjusted to provide a piecewise-linear approximation to a desired antenna pattern.