Power Synthesis At Low-THz Frequencies Based On Digital Phase Control

Terahertz (THz) technology is one of the research fronts in the microwave society. Among many technical challenges, achieving high-power THz radiation is one of the main obstacles of the THz technology developing recently. The research for this issue has been attracting far more attentions, and power synthesis is a very efficient method to solve this problem.In this paper, we investigate the possibility of power synthesis at sub-THz frequencies based on digital phase control, which can overcome the difficulty of phase alignment at these frequencies. We show that by theoretical analysis, such a power synthesis can enhance the efficiency of the final power synthesis. For demonstration, we implement a0.11THz prototype system employing impact avalanche and transit time (IMPATT) diodes.IMPATT diode should be assembled in the suitable cavity to get the best state. Using a simulation-and measurement-based design methodology, the impedance matching of the designed cavity is able to be simultaneously obtained at both the radio frequency (RF) bias and low-THz frequencies.IMPATT diode will achieve the objective frequency only via the sufficient stimulate. Experiment and detailed explanation of the RF and DC bias including principle analysis, design and chip based circuit are introduced corresponding to the requirement.In this dissertation simulation, we complete the measurement of the0.11THz prototype system. The experimental results comply well with analytical expectations. Analysis shows that the proposed approach is able to provide sufficient phase control precision, making it possible to be used in the power synthesis applications at low THz frequencies.