在現代無線通訊系統中,無論是在發射端或是在接收端,頻率合成器皆扮演 著非常重要的角色。其中又以鎖相迴路為主的頻率合成器大量地被使用。然而, 傳統的整數型鎖相迴路有著頻率解析度和迴路頻寬的設計衝突,因此分數型頻率 合成器較常使用於無線應用中,能同時擁有大的迴路頻寬與精準的頻率解析度。 三角積分分數型頻率合成器為最常被使用的一種架構,因為它的分數突波較 小,且三角積分調變器具有將量化雜訊移往高頻去的特性。在本論文中,於台積 電零點一八微米金氧半製程,實現了兩個三角積分分數型頻率合成器,其操作頻 率為2.4 GHz。採用LC 壓控振盪器,鎖相迴路整體的相位雜訊良好。 於本論文的附錄A,利用聯電九零奈米製程,實現了一個適用於超寬頻(UWB) 通訊系統第一組頻率 (3432, 3960 and 4488 MHz)的頻率合成器。此晶片擁有好的 相位雜訊輸出,並有極短的切換頻道速度 (2ns) 。 附錄B 為自行研發的基本數位電路邏輯閘的佈局圖,是設計於台積電零點 一八微米製程,一共三十個。此基本數位電路邏輯閘,可提供數位電路藉由相關 軟體來做自動繞線,產生佈局圖。
In the modern communication system, frequency synthesizers play an essential role either in the transmitting path or receiving path. Among several types of frequency synthesizers, the PLL-based frequency synthesizers are the most popular one. However, conventional integer-N frequency synthesizers suffer from the tradeoff between the loop bandwidth and the frequency resolution. Therefore, fractional-N frequency synthesizers are adopted to achieve both small frequency resolution and wide loop bandwidth. ΔΣ fractional-N frequency synthesizers, for its lower spurs magnitude and high-pass noise shaping ability, are most often adopted. Two ΔΣ fractional-N frequency synthesizers implemented in TSMC 0.18-um process are presented in this thesis. Operating at 2.4 GHz, with the LC-VCO, the synthesizers exhibit good phase noise. In appendix A, a low-power CMOS frequency synthesizer for mode-I (3432, 3960 and 4488 MHz) UWB MB-OFDM transceiver is presented. Implemented in UMC 90 nm process, the synthesizer exhibits good phase noise and fast switching time in 2 ns. In appendix B, a set of digital cells is established under TSMC 0.18-um process. Utilizing the digital cells, the layout work of a digital circuit can be auto-routed by the aid of some CAD tools.