A general look on time-modulated antenna array

From the perspective of diversity, spectrum utilization, and the hybrid processing in time domain and in frequency domain, this paper takes a general look and new perspectives on time-modulated antenna array. Some novel ideas, such as the synthesis of 4-D beampattern through 4-D source and the combination of retrodirective technique and the optimization of time-modulated frequency offset, are presented and discussed that may result in the further developments on such array. Finally, the full-wave analysis of the instantaneous and average behaviors on time-modulated antenna arrays is briefly introduced.