The Research Of Key Device Used In Terahertz Quasi-optical Detector

With the continuous development of Terahertz technology,Terahertz technology has been used in space,astronomy,atmospheric probing,communication and imaging,etc.In these application,the direction of the imaging is very popular.Highly sensitive THz quasioptical detector plays is an essential part of THz imaging system.The front of the THz quasioptical detector including THz schottky diode,THz dielectric lens antenna and IF matching network.This paper focus on designing THz dielectric lens antenna.Based on single-pixel dielectric lens antenna,we analyze and design a log periodic antenna,which works in 340 GHz.We analyze the principle of extended hemispherical lens,then we give the simulation models and results of the lens antenna.Owing to these,we have designed the lens antenna,which is composed by silicon.Then we produce the lens antenna,and test the far-field pattern.The optimized simulation results of the lens antenna are given.Using THz spectroscopy system,we analyze some materials.Due to analysis results,we choose nylon as the material of lens antenna's design.We also give the simulation models and results of the nylon lens antenna.Similarly,we produce the nylon lens antenna,and test the far-field pattern.Then,we compare silicon lens antenna to nylon lens antenna,and analyze the performance of these lens.Based on single-pixel dielectric lens antenna,we analyze the feasibility of extended hemispherical lens array antenna.We analyze the coupling and off-axis performance of array unit.The simulation results of the lens antenna are given.We find for 30 mm quartz lens,it can hold 4×4 antenna array.Due to flip-chip technology,the IF matching network is designed.At last,owing to detector's characteristic,we design a new assembly method.This method can aligner the axis of antenna and lens,and provide a well shielding environment,which can improve the performance.Six-dimensional tunably fixture can meet the requirements of locating the beam waist accurately and fine-tuned in multi-dimension.Thanks to these,we can proceed the test of quasi-optical detector conveniently.