Antenna Array for Amplitude and Phase Specified Near-Field Multifocus

The multibeam technique is an essential enabling design feature of the antenna array for wireless systems in connection with multiple users and multiple spots. In this paper, a method of developing an antenna array that features multiple focuses with specified amplitude and phase conditions in its nearfield region is proposed and discussed. A modeling algorithm considering phase compensation, superposition, and corresponding optimization strategy is defined in order not only to identify the spatial location but also to formulate the amplitude and/or phase delay of such multifocus. On the other hand, a pervasive antenna near-field equivalent model is used to augment the accuracy of the proposed model and at the same time to accelerate its calculation process. Criteria for designing a multifocus array and strengthening its spatial resolution are discussed. Examples of antenna array with different multifocus requirements are presented. The proposed method is finally verified experimentally through a prototyped near-field multifocus array system.