Research On Antenna And RF Filter Of Millimeter Wave Radiometer

Millimeter wave radiometer uses passive target energy to receive signal processing and target recognition.The millimeter wave radiometer has been widely used because of its unique advantages.It has better signal processing ability and higher target identification.Therefore,it is of greatly value in military,agriculture and environmental monitoring.The antenna applied to millimeter wave detection system is supposed to have low sidelobe and high gain performance.RF filter is supposed to have low loss and extra band rejection performance.According to the requirements of millimeter wave radiometer for RF front-end,the antenna and RF filter module in 35 GHz millimeter wave radiometer are studied in depth and the design is given.The main content of the thesis is as follows:First of all,We have discussed the research status of millimeter wave radiometer and have a clear understanding of its development trend.At the same time,We have studied the working principle of it,We combine the practical application background and the research of millimeter wave radiometer project for feasibility and superiority of this full power radiometer research program and the main technical indexes of 35 GHz millimeter wave radiometer are given.Because the front-end of the millimeter wave radiometer system plays a decisive role in the performance of the system,we focus on the antenna and filter of the radiometer system.Secondly,We analyse the design theory and method of horn antenna,microstrip antenna,and proposed the main technical indexes of millimeter wave radiation meter antenna,respectively using CST and HFSS software simulation of the center frequency of 35 GHz horn antenna and microstrip patch antenna,the simulation in VSWR and gain pattern to prove the superiority of horn antenna.The simulation performance is compared with the technical indexof millimeter wave radiometer antenna and the simulation performance of horn antenna can meet the requirements of millimeter wave radiometer antenna.The actual measurement results of the antenna entity are in good agreement with the theoretical simulation results of the horn antenna,and the performance of the antenna is ideal and the size is extremely small.It proves that the antenna can meet the needs of the project verifying the feasibility of the pyramid horn antenna design.Finally,We do the research the design theory and method of the RF filter and the main technical indexes of the RF filter in the millimeter wave radiometer are given.We have designed a parallel coupled microstrip line bandpass filter based on the design of the center frequency of 35 GHz and we finished simulation of filter design using ADS software.The millimeter wave radiometer design index of the RF filter have certain requirements so the design of the filter simulation principle diagram and band loss parameters were optimized,the final design can satisfy the actual needs of the parallel coupled microstrip line bandpass filter,and verify the feasibility and superiority of the design method of RF the filter.