CMOS開關鍵控調變器及應用於SATA3差動訊號雙向通道開關

Abstract

近年在有線及無線系統在微波頻段的應用有顯著的發展，並大大地改變人們的生活，手持行動裝置儼然已成為現在人生活的必需品。而在通訊系統中，常可見到各種的調變技術。本論文將介紹一個操作於1.9 GHz 之OOK調變器使用90奈米CMOS製程以及使用0.18微米CMOS製程應用於SATA系統的雙向開關。為了提升開關電路在饋入損失(Insertion Loss)、隔離度(Isolation)、開關速度、線性度的表現，應用相關技術於設計之電路：第一部分，將RF leakage消除技術應用於CMOS開關鍵控(OOK)調變器之開關；第二部分，在SATA3系統之雙向開關上，應用Body floating與Deep-n-well等技術，提升開關高頻下的表現。 在論文的第一部分，CMOS開關鍵控(OOK)調變器，使用複製電路(replicative circuit)來實現訊號消除的技術，來提高關閉下的隔離度；本電路的另一特色，是在開關切換On/Off變化下，依然保持良好的匹配到50 Ohm網路。文中展示具高隔離度的開關鍵控調變器，其操作頻率為2 GHz。量測結果顯示，在On/Off state下皆有達成良好的匹配，且隔離度提升至將近40 dB。 在論文的第二部分，將設計一個CMOS雙向開關，此電路操作頻率由DC- 4GHz，採用差動訊號電路架構，具有高達6.5 Gbps的傳輸速率，低Bit-to-Bit skew、饋入損失、交叉干擾(Crosstalk)，且有高隔離度，可應用於SAS2、SATA3、XAUI系統。使用Body floating與Deep-n-well 接高電壓等技術，來提升高頻的電路表現。文章中，敘述電路實現方式與模擬結果，及最後的佈局及模擬結果。

Over the few years, there are several significant developments that have been proposed in the domain of wire and wireless RF communication systems. This paper presents a 90-nm CMOS OOK modulator operating at 1.9 GHz and a differential bi-directional channel DC-4-GHz switch in 0.18-m CMOS. The proposed switch having a 6.5 Gbps data rate, high isolation, low Bit-to-Bit skew, insertion loss and crosstalk is suitable to SAS2, SATA3 and XAUI systems. Several techniques such as body-floating, DNW-to- Vdd and RF-leakage-cancellation are used in this thesis to improve the performance of the insertion loss, isolation, switching speed and the linearity. The ultrahigh isolation in off-state is achieved by using the RF leakage cancellation technique with replicative circuit implementation on CMOS on-off keying modulator. Moreover, the insertion loss and the isolation can be further improved in high frequency range by connecting the deep-n-well to Vdd and using body floating technique. The matching network used balun and transformer to sustain the input/output matching is matched 50 ohm. The measurement result shows that the isolation of the OOK modulator operating in 1.9 GHz is higher than 40 dB and the matching network can perfectly achieve 50 ohm while operating state of OOK modulator changes between on/off state.