Design of frequency-invariant broadband far-field sensor arrays

The theory and design of an array of sensors having a frequency invariant beam pattern over an arbitrarily wide design bandwidth is presented. A continuously distributed sensor is used to derive a frequency invariance property, and the problem of designing a practical sensor array is then treated as an approximation to this ideal continuous sensor. The resulting design methodology is suitable for 1D, 2D and 3D sensor arrays with arbitrary beam pattern (in both magnitude and phase) and results in a simple implementation. An important consequence of our method is that the primary filter applied to the output of each sensor is related to a slice through the aperture distribution. Results also implicate that sensor locations are not a crucial design consideration. An illustrative design example is given to demonstrate the method outlined.<>