Wide-band adaptive array processing using pole-zero digital filters

Conventional broad-band array processing is accomplished by linearly combining the outputs of tapped-delay lines attached to each sensor of an array. This type of processing can be interpreted as using an all-zero digital filter at each sensor to generate a frequency-dependent magnitude and phase shift (weighting) over the array operating bandwidth. A new array processing method is presented which uses digital filters having both poles and zeros to perform the frequency-dependent array weighting. Several algorithms for adapting the pole-zero array filters are introduced. Computer simulations are then presented demonstrating the potential for substantial improvement in broad-band interference nulling provided by pole-zero array processing.