Power synthesis at low frequencies in the sub-THz gap

Terahertz (THz) technology is one of the research fronts in the microwave society. In this paper, we investigate the possibility of power synthesis at low-THz frequencies based on discrete THz sources. We show that by applying precision digital phase control, such a power synthesis can be achieved, overcoming the difficulty of phase alignment at these frequencies. For demonstration, we implement a 0.11-THz prototype system based on state of the art F-PLLs and IMPATT diodes. Experimental results validate the proposed approach. With increased wide digital bit width, our method can be effectively used at all sub- and low-THz frequencies in the THz gap, providing an alternative thought to achieve high-power THz waves.