本論文主要目的是在LTCC上實現小型化且應用在UWB (3.1~ 4.9GHz and 3.1~8GHz)頻段的Balun，在論文中使用兩條金屬線之耦合線構成之balun已可實現第一種UWB頻段3.1~ 4.9GHz，實作結果頻寬約在2.68 ~ 5 GHz，頻帶內振幅差最大0.9 dB最小0.1 dB，插入損失在1.1 dB以內，相位差在8度以內，整體尺寸大小為2mm×1.25mm×0.814mm，但是對於第二種UWB頻段3.1~8GHz卻無法實現，所以本論文利用兩種增加頻寬的方法來實現UWB第二種規格3.1~8GHz :
1.改變接地面積的大小。
2.結構改用三條金屬線構成之耦合線。
由模擬與實作結果來看，利用這兩種方法的確可以在LTCC上實現頻寬由3.1到8GHz的Marchand Balun，尺寸大小為2012(2mm×1.25mm)。

The main purpose of this thesis is to realize the compact balun for UWB(3.1~4.9GHz and 3.1~8GHz) by using LTCC technology. In this study, the balun’s structure which was formed by two-line couplers can realize the first kind of specification (3.1~4.9GHz) for UWB. The measured bandwidth is 2.68 ~ 5 GHz. The measured amplitude and phase imbalances are less than 0.9dB and 8 degrees. The measured insertion loss is less than 1.1dB. The overall size is 2mm×1.25mm×0.814mm. To meet the second specification (3.1~8GHz) for UWB. Two methods expressed as follow are used to enhance the bandwidth of balun:
1.To enhance the bandwidth of balun by changing the area of ground metal.
2.To enhance the bandwidth of balun by introducing the three coupled lines instead of two coupled lines.

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