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Browsing by Author "Chu, Chin-Yi"

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    A Compact Design of Antenna Feed for 6 M S/X-Bands Mono-Pulse Auto-Tracking Ground Station
    (2015)
    Lee, Yun-Jui
    ;
    Huang, Vincent
    ;
    Yang, Ru-Muh
    ;
    Hsu, Ti-Hsiang
    ;
    Chen, Ming-Hui
    A compact S-band auto-tracking antenna feed for 6 m mono-pulse auto-tracking ground station is presented. It is designed to reduce the effect of blockage of the antenna systems and modify the orientation angle of the main reflector to align antenna boresight with a satellite. A circular waveguide is designed to connect to the septum polarizer for communication between the earth and LEO satellite. Based on the circular waveguide as an inner metal, a cylindrical metal is added as an outer metal to form a coaxial line for tracking LEO satellite. The uplink band of the antenna feed is from 2.025 to 2.12 GHz and the downlink band is from 2.2 to 2.3 CHz. The results show that the antenna gain of 6 m reflector is about 39.7 dBic and the 1-dBbeamw idth is 1 degree. The polarization isolation between sum and difference patterns is larger than 30 dB, and the axial ratio is lower than 1.1 dB within +/- 0.5 degree range.
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    Design of Antenna Feed for Mono-pulse Auto-Tracking Ground Station
    (2014)
    Lee, Yun-Jui
    ;
    Chen, Wei-Lin
    ;
    Yaung, Shan-Kuo
    ;
    Yang, Ru-Muh
    ;
    Chen, Ming-Hui
    An S-band auto-tracking antenna feed for mono-pulse ground station is presented. The uplink band is from 2.025 to 2.12 GHz and the downlink band is from 2.2 to 2.3 GHz. The feed is utilized to modify the orientation angle of the antenna to align antenna boresight with a satellite. According to the mono-pulse radar theory, the system structure can be divided into two parts, sum and difference channels. Sum channel is used for data transmission and the key component is a septum polarizer which generates circularly polarized electric fields. Difference channel is used to modify the antenna angle and the key component is a TE21 tracking coupler with signal combining circuits. The results show that the polarization isolation is larger than 40 dB, and the axial ratio is smaller than 1.4 dB.