Application of multiplicative array techniques for multibeam sounder systems

Abstract

Multiplicative array processing is well known for its narrow beamwidth and low sidelobe level, but the array gain is quite low. The effectiveness of such a system becomes lower, especially when the signal to noise ratio is low. Proposed some modification in terms of additional computation or hardware for improved array gain. The present work is devoted towards the study of a better beamforming method i.e. a multiplicative array technique with some modification proposEd. by Brown and Rowland. Their method is used for a multibeam sounder system. The modified multiplicative array system consists of 20-elements. The performance of the proposed system is compared with an additive, i.e. delay-sum array of 40-elements of a similar configuration. The performance comparisons are made in terms of vaetical beam patterns at different main beam steering angles of 5 degrees, 10 degrees, 20 degrees, 30 degrees, and normal incidence directions. The operating frequency is assumed to be 15 kHz. In addition, the vertical beam pattern of the multiplicative array is also presented for the normal incidence direction