高清晰多媒體介面HDMI（High-definition multimedia interface）是一種全數位化影像及聲音傳送介面，在現在的科技進步之下，在電腦上已經是非常普及的輸出裝置了，但是在這樣的高速訊號的傳輸之下，電磁干擾（Electromagnetic Interference，簡稱EMI）一直是工程師要去解決的問題，時常為了解決HDMI的EMI問題加入電子的對策，往往導致眼圖無法達到標準，或者是在機殼上做大量的屏蔽，使成本提高。
　　本論文使用有裝載HDMI介面的筆記型電腦做研究，此筆記型電腦產品裝置的平台為英特爾（Intel）處理器，此平台提供了幾個參數給工程師在基本輸出輸入系統（Basic Input/Output System，簡稱BIOS）裡調降HDMI訊號強度，本論文在量測後，分析各種常見及本文提出的解決方案，結果顯示以往常見的解決方式改善效果有限並且增加成本，而本論文所提供的方式，HDMI可在不需要增加成本以及更改電路設計的情況之下，成功的控制眼圖及EMI的品質，其BIOS調整方式有下列三種：

1.只需要眼圖Pass的情況可以選擇預設值1000mV0.0dB或調降位準強度至800mV0.0dB。
2.需要EMI可以Pass的情況，可以將位準強度調降至800mV0.0dB或600mV0.0dB。
3.若是要眼圖及EMI同時要達到法規標準，將位準強度調降至800mV0.0dB即可。

HDMI (high-definition multimedia interface) is a digital interface to transfer image and sounds. It is a common output device for the development technology in recent years. However, EMI (Electromagnetic Interference) is an important issue in such high speed transmission and a lot of problems need to be resolved. Some techniques without extra cost for reducing EMI issues deteriorate eye diagram and some techniques increase the cost by placing numerous shielding on metal chassis.
In this thesis, we will focus on the research for note book using Intel processer with HDMI output. It provides a few modification parameters to adjust the signal strength in the Basic Input/Output System (BIOS). It is found that, without increasing the cost and changing the layout, the eye diagram and EMI could be compromised by our proposed techniques for adjusting the level output of BIOS as the following:

1. To satisfy the criteria for eye diagram, the level strength can be set as the default value 1000mV0.0dB or reduce to 800mV0.0dB.
2. To satisfy the criteria for EMI, the level strength can be set as 800mV0.0dB or 600mV0.0dB.
3. To satisfy the criteria for both eye diagram and EMI, the level strength must be set as 800mV0.0dB.

Finally, compared to the conventional techniques, our proposed techniques can improve both eye diagram and EMI without increasing the cost and changing the layout.

致謝 I
摘要 II
目錄 V
圖目錄 VII
表目錄 X
第一章	緒論 1
1.1 研究動機 1
1.2 電腦代工廠對EMI遇到的問題 2
1.3 問題陳述 3
第二章	何謂電磁干擾與環境介紹 5
2.1 何謂電磁干擾及電磁相容 5
2.2 電磁環境 7
2.3 EMI產生原因 7
2.4 電磁相容防治規範 8
2.5 電磁干擾測試場地要求 12
2.6 HDMI介紹 14
2.7 眼圖介紹 15
2.8 BIOS介紹 16
第三章	實驗方法與對策介紹 17
3.1 實驗架構 17
3.2 量測方法 18
　 3.2.1 眼圖 18
   3.2.2 輻射干擾 20
3.3 量測環境介紹 23
3.4 共模電感的使用 25
3.5 並聯電阻的使用 27
3.6 BIOS調降訊號強度 27
第四章	量測結果與數據分析 29
4.1 原始預設值的HDMI量測結果 29
4.2 實驗一：HDMI使用共模電感的量測結果 32
4.3 實驗二：HDMI使用並聯電阻的量測結果 35
4.4 實驗三：HDMI使用BIOS調降訊號強度 38
4.4.1 調降至600mv0dB量測結果 39
4.4.2 調降至800mv0dB量測結果 41
4.5 量測結果分析 44
第五章	結論 46
參考文獻 48

圖目錄

圖1.1 HDMI於PCB的走線 3
圖1.2 HDMI之EMI超標量測結果 4
圖2.1 電磁相容所包含的項目 6
圖2.2 電磁干擾的三大要素 7
圖2.3 Radiation測試場地圖 13
圖2.4 Radiation測試配置圖 13
圖2.5 眼圖 15
圖2.6 眼圖的構成 16
圖3.1 論文實驗的HDMI線路圖 18
圖3.2 眼圖量測配置照 19
圖3.3 於示波器所顯示的眼圖 19
圖3.4 Radiation天線水平極性量測圖 20
圖3.5 Radiation天線垂直極性量測圖 21
圖3.6 電波暗室量測控制儀器 22
圖3.7 數位取樣示波器 23
圖3.8 頻譜分析儀 24
圖3.9 共模電感 25
圖3.10 共模電感原理圖  26
圖3.11 線路圖上的共模電感圖 26
圖3.12 線路圖上的電阻位置圖 27
圖3.13 BIOS的HDMI Level strength控制介面 28
圖4.1 1000mV0.0dB原始狀態的眼圖量測圖D0 30
圖4.2 1000mV0.0dB原始狀態的眼圖量測圖D1 30
圖4.3 1000mV0.0dB原始狀態的眼圖量測圖D2 30
圖4.4 1000mV0.0dB原始狀態Radiation量測結果 31
圖4.5 主機板HDMI訊號線加上共模電感 32
圖4.6 HDMI加上共模電感眼圖量測圖D0 33
圖4.7 HDMI加上共模電感眼圖量測圖D1 33
圖4.8 HDMI加上共模電感眼圖量測圖D2 33
圖4.9 HDMI加上共模電感Radiation量測圖 34
圖4.10 主機板HDMI訊號線並聯電阻 35
圖4.11 HDMI 並聯電阻眼圖量測圖D0 36
圖4.12 HDMI 並聯電阻眼圖量測圖D1 36
圖4.13 HDMI 並聯電阻眼圖量測圖D2 36
圖4.14 HDMI加上並聯電阻Radiation量測圖 37
圖4.15 主機板還原原始狀態 38
圖4.16 BIOS調降HDMI強度介面 39
圖4.17 800mV0.0dB 眼圖量測圖D0 40
圖4.18 800mV0.0dB 眼圖量測圖D1 40
圖4.19 800mV0.0dB 眼圖量測圖D2 40
圖4.20 800mV0.0dB Radiation量測圖 41
圖4.21 600mv0dB 眼圖量測圖D0 42
圖4.22 600mv0dB 眼圖量測圖D1 42
圖4.23 600mv0dB 眼圖量測圖D2 42
圖4.24 600mV0.0dB Radiation量測圖 43

表目錄

表2.1 國家標準總號名稱及對應的CISPR規範 10
表2.2 CISPR 22傳導干擾限制值 11
表2.3 輻射干擾限制值 12
表4.1 眼圖量測比較 44
表4.2 Radiation量測比較 45
表4.3 眼圖及EMI整體比較 45

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