In this paper, some conventional amplitude tapering windows are applied to a linear array antenna to investigate stability of array performance in the presence of tapered amplitude errors. The array performance degrades, if it is introduced with the tapered amplitude error. This performance degradation problem due to tapered errors can be solved by using a higher immune tapered window. This paper proposes that Gaussian excited linear array (GELA) provides higher immunity against these applied amplitude errors compared to the other window techniques. To measure the immunity against amplitude errors, two Side lobes are compared before and after feeding errors. It is shown that the proposed GELA beamformer offers only a maximum of side lobe level (SLL) deviation from the expected. It provides as good directivity as uniformly excited linear array (UELA) tapered beamformer. Also the GELA beamformer offers SLL which is at least below the SLL of UELA.