A new method is proposed for suppressing the grating lobe (GL) by pulse power transmission from an array antenna. GL suppression relies on the fact that the maximum electric field value is not synthesized by the waves from the array antenna at the undesired points even if the maximum electric field is attained at the desired receiving point, because the pulses emerging from different antenna elements do not overlap. Two computer simulations are carried out to confirm this suppression effect. In the simulation using a two-element array antenna with all element spacing exceeding one wavelength, the GL suppression effect is confirmed with a pulsed wave even though the GL is generated with a continuous wave. In pulsed power transmission simulation with many elements, the GL suppression effect is enhanced with an increasing number of elements. It is also found that the effect increases as the pulse width becomes smaller. (C) 2004 Wiley Periodicals, Inc.