On the number of degrees of freedom used by an adaptive antenna array in a nonnarrowband noise environment
Abstract
The relative measures of the eigenvalues of the noise covariance matrix of an adaptive array which is subjected to a nonnarrowband jamming source are investigated. These measures are important because they determine the convergence rate and the upper limit of the output signaltonoise ratio of the adaptive array. It is found that the adaptive array's performance as measured by the output signaltonoise ratio degrades in quantum jumps as the input noise bandwidth increases. A methodology is developed whereby given the number of elements of the array, the array spacing, the array element antenna pattern, the power, and direction of arrival of an external jammer, these discrete bandwidths of the jammer that limit the output signaltonoise ratio can be calculated.
 Publication:

Naval Research Lab. Report
 Pub Date:
 September 1982
 Bibcode:
 1982nrl..reptQR...G
 Keywords:

 Adaptive Control;
 Antenna Arrays;
 Degrees Of Freedom;
 Electromagnetic Noise;
 Jamming;
 Antenna Radiation Patterns;
 Covariance;
 Eigenvalues;
 Matrices (Mathematics);
 Signal To Noise Ratios;
 Communications and Radar