A method for suppressing grating lobes of wideband reconnaissance DBF

As to the problem of grating lobes suppression for wide-band reconnaissance DBF, a new method is proposed based on the technology of virtual antenna. The array antenna in the method uses main array antenna plus auxiliary array way. DBF algorithms in the method don't need to know the prior knowledge of reconnaissance signal and don't need complex matrix inverse operation, instead of it, the two kinds of fast calculation algorithm for the signal of virtual unit is used. Finally, the method not only suppresses grating lobe for broadband DBF effectively, but also improves the antenna angular resolution. At last, a 1-D and 16-unit array antenna is studied as an example for simulation analysis. The simulation results show that the proposed method can maximum suppress the grating lobe 15dB, and decrease the equivalent antenna beam width to half of the original antenna. So, the validity and superiority of this method is verified.