本論文為超寬頻系統收發端射頻前端電路模組之研究，論文中將應用ADS電路模擬軟體及HFSS電磁模擬軟體進行電路設計、探討與分析，並以實測驗證電路之效能。
論文首先探討發射端射頻前端電路模組，並建立脈衝電路之關鍵元件 - 步級回復二極體之等效模擬參數，以提高設計脈衝產生電路的準確性。接著設計可產生高斯脈衝及單週期脈衝的脈衝產生器。此外為避免超寬頻系統與無線區域網路之間潛在的干擾，吾人在脈衝整形電路上引入缺陷接地架構設計一款帶拒濾波器，使得該超寬頻脈衝在無線區域網路的頻段(5至6GHz)具有帶拒的特性。
在接收端射頻前端電路模組方面，吾人先以文獻裡微波取樣器進行改良，經模擬及實測結果進行動態範圍及轉換線性度的分析探討。接著將微波取樣器中的魔術T電路進行微型化設計，該新型電路結構為三層板架構，利用微帶線與孔槽線間的電場耦合特性，並搭配取樣二極體來實現微波取樣器，經與文獻之改良電路比較，發覺其動態範圍及轉換線性度均更為優良，且電路尺寸縮小75％，故實現微型化及高效能之微波取樣器。
本論文在超寬頻系統射頻前端電路模組的設計方面，具有相當的應用價值，並建立未來研究之基礎。

This thesis investigates the RF front-end circuit module for the ultra wideband system (UWB). In the study we use the circuit simulation tool Agilent ADS and the electromagnetic simulation software Ansoft HFSS to perform the circuit design, analysis, and verification.
Firstly, we deal with the RF front-end circuits in the transmitter. By building up the equivalent circuit model of the step recovery diode (SRD), the performance pf the pulse generator can be substantially enhanced. Two pulse generators, the Gaussian pulse generator and the monocycle generator, are designed, fabricated, and experimentally demonstrated. In addition, to alleviate the potential interference between the UWB systems and the WLAN radios, in Chapter 3 we introduce a three-order band-rejection filter to the pulse shaper at the frequency range of 5 to 6 GHz by utilizing the defected ground structure (DGS).
In the study of RF front-end circuits in the receiver, we first reproduce a microwave sampler in the literature on a low-cost FR4 substrate. The analysis including dynamic range and conversion linearity are discussed in terms of both simulated and measured results. To miniaturize the circuit dimension of the microwave sampler, in Chapter 5 we proposed a new magic-T circuit design. This novel magic-T is realized by a three-layered fabrication process with the help of electrically coupled microstrip lines through slotted aperture on the common ground plane. The new microwave sampler is composed of this miniaturized magic-T and the sampling bridge with two Schottky diodes. The experimental results demonstrate significant improvement on both dynamic range and conversion linearity, and the percentage of size reduction is as high as 75%.
This thesis provides some valuable information for practical UWB applications and also establishes the fundamental building blocks for future study on pulse radios.

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