Research On 220GHz Bandpass Filter And Power Combiner

Terahertz(THz)wave frequency is between 100GHz～10THz,has high penetration,high resolution and other good characteristics,has a wide range of applications in terahertz communication,astronomy and other fields.There are many problems in the development and application of traditional electronic devices in terahertz band.In this thesis,the application of microstrip hairpin band-pass filter and 32 path waveguide power synthesizer in terahertz band will be studied.In the first part of this thesis,the design of 220 GHz microstrip hairpin bandpass filter is introduced.Electromagnetic simulation software HFSS is used to establish the model and simulation optimization of the microstrip hairpin band-pass filter.Some problems that will be faced in the actual processing are discussed.In order to solve the problem that the actual insertion loss of the filter increased significantly due to the conductive silver paste layer under the quartz substrate in the actual assembly process,the structure of the hairpin filter was improved and the suspended microstrip structure was introduced.The final simulation results show that the compact structure of the microstrip hairpin bandpass filter,the insertion loss is less than 2d B,the return loss is less than-20 d B,the bandwidth is up to 20 GHz,and the out-of-band suppression is 20 d B.The microstrip hairpin filter can significantly reduce the additional insertion loss caused by the conductive silver paste,and has a broad application prospect in the terahertz frequency band.In the second part of this thesis,the basic principle of terahertz band power combine technology is introduced.Combined with the current manufacturing and assembly technology,the 220 GHz 32 path waveguide power combine network is designed,and the corresponding model is established,simulation optimization is carried out.This 32-path waveguide power combine network consists of three parts: 16-path waveguide power synthesizer based on circular waveguide TE01 mode,220 GHz rectangular waveguide TE10 mod-circular waveguide TE01 mode converter,magic T.The first part is a 16-path waveguide power combine network,which consists of a16-path branch waveguide and a two-stage matching circle in the center.The second part is the mode converter,which converts the rectangular waveguide mode TE10 to the circular waveguide mode TE01.The third part is the magic T structure.The part consists of waveguide arm and impedance matching element.The power combine network composed of these three parts finally realizes the WR-4 port excitation and the 32 channel combine function of WR-4 port output.The simulation results of the back-to-back structure show that the insertion loss is less than0.5d B,the return loss is less than-13 d B,and the output of watts can be achieved when the saturation output power of the chip reaches 19 d Bm.The combine network has the advantages of high power capacity,high combine efficiency and small size,which can be processed and assembled by micro-milling process.The research in this thesis will provide important technical support for the development of miniaturized terahertz source and system.