The active adaptive antenna array system

The active adaptive antenna array system (AAAAS) is a self-focusing antenna array. Phase-lock loop-type circuits are used to automatically adjust the phases of signals received on the elemental antennas of the array so that the received signals can all be added in phase or coherently. The AAAAS is active in that it automatically searches for, locks onto and tracks a source. Furthermore, the system 1) is adaptive to changes in antenna spacing, 2) is adaptive to changes in signal level and noise spectral density, 3) uses the incoming signal to automatically and electronically collimate the antenna array beam and 4) can have its aperture amplitude distribution readily changed. A theoretical study and detailed description of two particular configurations of the AAAAS is given. The theory of operation of the system has been experimentally verified on a simulated system in which audio frequencies were used.