Abstract: A nondispersive array antenna comprises a linear primary radiator array in the form of a slotted waveguide emitting high-frequency waves toward a linear secondary radiator array including an acute angle .alpha. with the primary array, this angle .alpha. being approximately equal to (.pi./4) -(.theta..sub.o /2) where .theta..sub.o is the angle included by the emitted beam with the perpendicular to the waveguide in the plane of radiation. The secondary array includes a row of elemental radiation receivers on the side facing the primary array and as many elemental radiation emitters on the opposite side; each radiation receiver is linked to a respective radiation emitter through a coupling introducing a predetermined phase shift between incoming and outgoing radiation, these phase shifts compensating for the phase displacement occurring along the arrays in the free-space propagation of the waves from one array to the other.