摘要
本論文的主要目的是設計、模擬、製作Ku頻帶的直接廣播衛星接收系統中的低雜訊放大降頻器。為考量商業化，在符合規格的前提下，針對電子元件的選擇、電路板的佈線，製作出符合全球直接廣播衛星接收頻帶之低成本、小型化的低雜訊放大降頻器。 本論文主要分成三大部份：第一個部份介紹直接廣播衛星接收系統，算出連接預算，並由規格中推算出特性預估以規劃元件的使用。第二部份針對四個模組：低雜訊放大器、鏡像抑制濾波器、介質諧振振盪器、混頻及中頻放大器，作設計、模擬與製作，並針對各個模組作測試。第三部份結合以上模組作整體小型化的電路板佈線，其面積可縮小至63.5 mm 23.5 mm之水準，因而可降低電路板及機殼的成本。並對整體作量測與調整，主要測試結果中，增益在50 ~ 60 dB之間，雜訊指數低於1.0 dB，本地振盪器之相位雜訊可達到-70 dBc / Hz ( @ 1KHz )、-86 dBc / Hz ( @ 10KHz )、-105 dBc / Hz ( @ 100KHz )。與規格做比較，所有測試結果皆能符合規格。
並列摘要
The purpose of this thesis is to design , simulate and develop a Ku Band low noise block down-converter . Considering commercial application , we focus on the selection of electric components and the layout of print circuit board to develop a low cost small size universal low noise block down-converter. This thesis consists of three parts : The first part introduces the direct broadcasting system , calculates the link budget , and selects appropriate components to meet the specifications . The second part designs , simulates and measures four modules : low noise amplifier , image rejection filter , dielectric resonator oscillator , and mixer with IF amplifier MMIC . The third part integrates these four modules to make a small size layout . The size of the layout is 63.5 mm 23.5 mm that can reduce the cost of PCB and housing . The overall gain of this low noise block down-converter is between 50 ~ 60 dB by measurement , the noise figure is below 1.0 dB , the phase noise of local oscillator is -70 dBc / Hz ( @ 1KHz )、-86 dBc / Hz ( @ 10KHz )、-105 dBc / Hz ( @ 100KHz ) . Comparing these measurement results with specifications , all measurement results are conformed to specifications .