Investigations On Terahertz Transmission Line And Antenna Technology

As a fast-growing and extremely important frontier research field,terahertz(THz)science and technology has great potential applications in different fields such as high-speed wireless communication,radar,medical imaging,security inspection,radio astronomy and electronic warfare.THz science and technology also has a great strategic significance in promoting national economic development and strengthening national security construction.Substrate Integrated Waveguide(SIW)has the advantages of high integration,high power capacity,low cost,large-scale production,high precision and so on.It is a promising candidate for developing low cost planar terahertz transmission line.In order to effectively study the loss characteristic of terahertz SIW as a transmission line,it is necessary to design a high-performance terahertz SI W-to-rectangular waveguide based on actual test considerations.In addition,terahertz antennas are a key part of terahertz communication and radiation systems,its performance will directly affect the the performance of the entire system.The realization of compact and high gain terahertz antenna using low cost process is a valuable research direction.In this paper,the following main work is done for the two aspects of terahertz transmission line and antenna technology:1.At first,the development of terahertz science and technology is summarized.Then,the research background and development of terahertz transition and terahertz antenna are introduced,respectively.Then,the basic theory of rectangular waveguide transmission,integrated waveguide design and geometrical optics are expounded.2.A terahertz SIW-rectangular waveguide transition is investigated.The effect of the switching structure on the resonant point in the transmission coefficient is discussed in detail.The D-band and G-band SIW transmission line is fabricated by using a low cost commercial PCB technology and measured in the experiments.The transmission loss per guided wavelength for D-and G-band SIWs and the loss of the single fin-line transition are extracted and analyzed,respectively.And the fluctuation existed in the extracted transmission loss is analyzed.The feasibility of this scheme is proved to be a high performance terahertz SIW-rectangular waveguide transition,and also effectively explored the loss characteristic of terahertz SIW as a transmission line.3.A terahertz high gain metallic lens antenna is investigated.The design principle and process are described in detail.The phase compensation effect of the lens structure on the wide frequency band is theoretically extracted and analyzed.The low cost metal milling process is applied to the 140 GHz and 412.5 GHz antenna,and then the S parameters,gain and radiation pattern were measured in the THz chamber,and the antenna loss was analyzed.The results show that the measured maximum gain of the 140 GHz and 412.5 GHz antennas in the corresponding frequency bands is 27.2 dBi and 27.7 dBi,respectively.This work demonstrates the compact high-gain terahertz antenna can be realized by using the metallic lens structure with the low cost commercial milling process.