Space-Time Modulated Wideband Array Antenna

This letter generalizes the use of linearly frequency modulated (LFM) continuous-wave waveform and time delays for frequency diverse array (FDA) functionality implementation to a general space-time modulated (STM) array antenna, which imposes no specific requirements on the transmitted waveforms. It uses diverse time delays instead of diverse frequency increments to implement the FDA. The transmit beampattern characteristics of the STM array under a general pulse waveform including monochromatic, LFM, and LFM pulse with Gaussian envelope cases are analyzed. Moreover, an STM wideband eight-element antenna operating in 4-6 GHz is designed and implemented. It is shown that STM generates autoscanning beampattern characteristics, which are rather different from that of a conventional phased-array antenna and of great importance in some specific radar and communication applications.