Wideband Beamforming Using Modified Farrow Structure FIR Filtering Method for Sonar Applications

A novel wideband beamforming method is proposed where the beamforming is achieved by using Modified Farrow Structure FIR Filtering method. This method provides efficient time delay compensation since it considers only the fractional part of delay unlike other time domain FIR filtering methods. The simulation results show the magnitude response of Modified Farrow Structure FIR Filter is almost unity up to half of the nyquist frequency which is most desired in performing time delay compensation for wideband beamforming in sonar applications.

1. Introduction

Wideband beamforming has found applications in various areas such as sonar, radar, communications, seismology, medical diagnosis, acoustics and so on [1] . In [3] , beamforming has been implemented using FFT techniques for broadband active sonar. In [4] also, frequency decomposition FFT beamformer has been used for low-probability-of-detection navigation by ROV or AUV. In [5] , wideband beamforming is achieved based on subbanding for phased array radar applications. In Biomedical applications [12] , adaptive wideband beamforming has been used for fetal heart monitoring, tissue hyperthermia, hearing aids etc. In [13] , digital wideband beamforming using phase compensation, Matrix algorithm, delay compensation using frequency domain and Block method has been discussed for sonar applications. Hence, wideband beamforming is still a research topic in the past few decades because of its challenges.