Application of Bridge Function Sequences in Passive Beamformer

Abstract

This paper provides a new kind of passive beamformer which uses bridge function sequences as spreading sequence weights. The passive beamformer uses pseudorandom spreading sequence as weight of signal from each antenna element. Then it forms spatial radiation pattern by combining these signals. It can track and locate multiple objects’ positions simultaneously without the need of phase shifters and attenuators and any adaptive electronic beamsteering. And its antenna array can be any arbitrary geometry displacement. It can discriminate directions of arrival with as high angle resolution as 1.40 when there are 2000 elements in the antenna array.  We use bridge function sequences as its pseudorandom spreading sequence weights.  Owing to Bridge function sequences with better cross correlation characteristics, the passive beamformer gets better performance promotion than ones with Walsh function sequences as spreading sequences.