Abstract: Since the complex coupling between end-fire antenna elements，high side lobe level is produced without high directivity and gain when the space of the end-fire antenna array is less than 1.5λ. In order to improve the gain and restrain the coupling，the space of the array should be increased but the grating lobe is produced concurrently. Digital virtual end-fire antenna array——a new method that virtual element interpolation based on the plate end-fire antenna array is proposed to restrain the grating lobe. Then，the far field patterns are compared and analyzed between calculation result of the virtual endfire antenna array and CST simulation result of the original end-fire antenna array. Finally，from the simulations and practical measurement，the validity of the new method in grating lobe restraining is confirmed.