A study of a de-focused adaptive array using a finite distance signal source

The performance of a de-focused Applebaum type adaptive array under the assumption of a finite distance signal source is studied. An approximate expression for the output signal-to-noise ratio (SNR) is obtained as a function of the steering distance and the steering angle. From that expression, a rule of thumb is drawn to determine both the steering angle and the steering distance which result in a given loss.