Low sidelobe patterns from thinned arrays using multiplicative processing

The paper describes a new technique for achieving low-sidelobe directional patterns (-35 dB) from thinned arrays. The concept employs multiplicative processing and is therefore restricted to receiving arrays. It is shown that a total of about 3N elements can synthesise a pattern corresponding to a filled array of N2 elements so that large thinning factors, in excess of 90%, are realizable for lirge numbers of elements and without degradation of sidelobe performance. The basic concept is also demonstrated experimentally with a 6-element array. It is shown that this design is more susceptible to the effects of random phase errors compared with conventional arrays and the multiplicative signal processing can also lead to problems of multiple-source cross products under certain situations.