| Summary: | 碩士 === 國防大學中正理工學院 === 電子工程研究所 === 95 === This thesis is illustrative that how to design a single aerial system radar with frequency modulating continue wave (FMCW) technology. The operation frequency of aerial system is a 24GHz and the components of it are waveguide、polarizer、space coupling and horn antenna. In this thesis, we utilize HFSS software to proceed simulate analysis of all aerials’ components, and analyze the changing data of waveguide’s radius and length, each section size of space coupling, length of rectangular polarizer, length and waist’s width of butterfly polarizer, and so on.
By the result we can know the waveguide’s radius is 4.655mm and the three sections size of space coupling are cone length 4mm at left , cylinder length 4mm in the middle, and cylinder length 5.2mm at right. When the radius is 2mm and it can get the centre frequency 23.9GHz and the return loss ratio is 56.95dB. As the waveguide and space coupling compose together and put into 16mm rectangle polarization machine, the waveguide can get around 1.15 axel ratios during 22-26GHz range. If change the rectangle polarizer to be a butterfly polarizer of which length is 20mm and waist length is 14mm and the axial ratio can improve at around 1.1, and the return loss rate will get larger bandwidth than rectangle polarizer.
Use these systems, such as waveguide, space coupling, butterfly polarizer, and horn antenna during 22-26 GHz the return loss rate can maintain at least 18dB and the axial ratio at around 1.1. The gain and direction in 24GHz are 25.28dB and 3dB, and the volume is around 85mm*85mm*155mm, and it is easier for manufacture. It also can reduce the cost and simplify the construction, and it even can provide a reference for developing high accuracy level gauge and it can spread for short distance FMCW wave radar and make the single antenna signal communication system.
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