Investigations On Terahertz Beam Scanning Antenna And Planar Filter

Terahertz(THz)science and technology,as the frontier research field of interdisciplinary research,has drawn the widespread attention and it is of important scientific research significance and potential application value in its development.As one of the important research directions of THz science and technology,THz antenna is a key device in numerous THz wireless systems,the performance of the THz antenna affects the overall system performance.High gain and the beam scanning antenna can significantly improve the performance of the whole system,such as THz wireless communication system,radar system,imaging system and so on.Therefore,it is of great significance to design high-gain THz beam scanning antenna.As the frequency-selective device in a THz system,the filter can filter out unwanted signals and noise to improve the signal-to-noise ratio(SNR)of the system.Substrate Integrated Waveguide(SIW)as a kind of transmission line which has the advantages of low loss,high Q value,high power capacity,and easy integration with a planar circuit,is very suitable for designing high-performance,easy-to-integrate THz filters.Hence,this paper makes a detailed study on high-gain THz beam scanning antenna and SIW THz filters.The detailed organizations are as follows:Firstly,the paper gives a brief overview of the THz science and technology,reviews the current research background and status of terahertz antennas and filters,and briefly introduces the types of beam scanning antennas.Secondly,a terahertz high-gain beam scanning antenna operating at the WR-2.2 frequency band(325-500 GHz)was designed by using the principle of double parabolic cylindrical reflector structure and mechanical scanning.The paper describes the working principle of the antenna and the design process in detail,and the low-cost metal milling technology are used to fabricate the antenna.Then the S-parameters,radiation patterns and gains were measured in the THz chamber.The measured results show that the reflection coefficient better than 15 dB over the entire WR-2.2 band.The beam of the antenna can be scanned within the range of-60° to+55°.The measured gains are all above 33.17 dBi and the maximum one is up to 38.05 dBi.Overall,the measured results of the antenna match well with the simulated.The experimental results indicate that the high-gain THz beam scanning antenna can be realized by using low-cost metal milling technology.Finally,the SIW technology is introduced and used to design two different topologies SIW filters with center frequency at 400 GHz.Then the tolerance analysis is carried out on the key structural parameters and the material property parameters.In addition,the effect of the surface roughness on the performance of filter was discussed by means of the electromagnetic simulation software HFSS.