Research And Design Of Terahertz Wireless Communication System

According to Edholm’s law, the bandwidth demand of people for short-distance wireless communication has doubled every 18 months over the last three decades. In order to provide a sufficiently high communication bandwidth, using higher carrier frequencies will become a necessary means, which requires the communications carriers to expand into the terahertz band in the future. Thus, terahertz wireless communications has become an important research topic for next-generation wireless short-range communication. Currently, there are two methods to develop terahertz wireless communication system. One way is to use the microwave frequency doubling technology. Another approach is to direct modulate THz source. In this paper, different from both, we study a novel terahertz wireless communication system based on spatial direct modulation mode. We study the transmission mechanism of terahertz waves, terahertz modulating and demodulating technologies and communication codec technologies. And we focus on the spatial direct modulation mode of terahertz wave. According to those studies, we have constructed 330 GHz carrier terahertz frequency wireless communication system to achieve the wireless transmission of pictures and other files.Firstly, the paper studies the terahertz transmission characteristics in the atmosphere. According to the oxygen and water vapor absorption spectrum, we study the oxygen and water vapor absorption characteristics for 0-1THz band. Then, we establish the transmission channel model of THz band in the atmosphere and provides the transmission windows those have lower atmospheric attenuation rate.Followed, We focus on exploring the structure of combining silicon and graphene(Graphene on Silicon, GOS), and have developed a new type of terahertz modulator with 1MHz modulation rate, over 50% modulation depth and 0.2-2THz frequency band. Those prove that GOS can be use as a good THz wave modulator. Further we establish the GOS-based terahertz wireless communication system model.Finally, the paper design a signal codec method which can be used for GOS modulator by the way of combining hardware and software. Based on this study, we design and build 330 GHz terahertz wireless communication system based on GOS, and it has achieved a communication rate of 500 kbps.Through the study of 330 GHz wireless communication system based on spatial direct modulation mode, this paper provides a important research idea and direction for the study of THz wireless communication system, especially the development of a communication system over 300 GHz.