A multichannel signal processor IC [for sonar]

One particular mode of active sonar signal processing is that of Doppler Processing, where a narrowband transmission and a spectral analysis receiver use the Doppler shift in frequency to discriminate moving wanted targets from stationary unwanted ones, such as returns from the sea surface or sea bed. A bank of filters matched to the transmission pulse duration provides the essential element of a Doppler processor but typical sonar parameters result in the requirement for very narrow bandwidths and a large number of filters to cover the range of anticipated Doppler shifts in frequency. Increasing the filters´ bandwidths before detection but maintaining an appropriately narrow post-detection bandwidth eases the design problems without appreciably sacrificing overall detection performance. Such an approach has resulted in the integrated circuit design to be described