| Summary: | 碩士 === 國防大學中正理工學院 === 電子工程研究所 === 90 === This paper presents the design of a low noise block-converter (LNB) using a frequency-conversion type active integrated antenna (FCAIA). A planar microstrip-circular-slot antenna, which is easier to integrate with other components, will replace the rectangular waveguide in conventional LNB. A self-mixing oscillator (SMO) with single transistor is designed to combine the function of local oscillator and mixer. Then, it is integrated with proposed antenna to complete the design of the FCAIA. Satellite signals received from FCAIA is direct converted to IF range. To properly filter the IF signals, a microstrip-ring filter having both the properties of fixed-frequency-rejected and low-pass filters is proposed. It is also applied to the design of SMO as the role of resonator, replacing dielectric resonator that is generally used in conventional LNBs. A high gain IF amplifier must be used to amplify the signal level to conform the specification of the direct broadcast satellite system. The proposed design of LNB will simplify the circuits of conventional ones. It’s also easier to manufacture the planar array antenna, which is easy for setting. In future, we can apply the architecture presented in this paper to design the integrated circuit of the receiver in Low Geo Orbit systems.
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