使用主動負載之吉伯特混頻器

Gilbert Cell Mixer Using Active Loads

吳心宇(Hsin-Yu Wu)

指導教授 ： 盧信嘉

國立臺灣大學/電機資訊學院/電子工程學研究所/碩士(2015年)

https://doi.org/10.6342/NTU.2015.10732

摘要

本論文主要研究偵測生物訊號之連續波雷達中接收路徑上之降頻混頻器，運用電磁波偵測生活周遭的具體訊號一直是人類努力的目標之一，其中非接觸式、用以偵測生物訊號的督普勒雷達(Doppler radar)近年來開始引起各方學者們的興趣。
本論文前半段由偵測生物訊號之連續波雷達開始介紹，並簡介混頻器於雷達中的用途，隨後分析各種不同混頻器之功能與架構。其中吉伯特混頻器為主動混頻器中最為熱門的架構，亦有許多文獻提供了增進吉伯特混頻器效能的方法。
後半段提出一種新的架構為交叉耦合對之主動負載吉伯特混頻器，能夠同時提高射頻端電晶體的互導以及輸出端的負載，亦不會提高通過負載的壓降，並使得轉換增益有效的提升。再透過電阻回授反向緩衝放大器架構之阻抗轉換放大器連接於混頻器輸出端，使混頻器對下一級電路的輸入阻抗較不敏感，解決原電路振盪的可能性。
本論文是以TSMC 0.18μm CMOS製程，設計主動負載架構之吉伯特混頻器，中心頻率在24GHz，使用ADS及Sonnet軟體模擬驗證，晶片佈局尺寸為 ，並於國家晶片中心進行高頻量測驗證，證實此主動負載架構能夠實現高電壓轉換增益之降頻混頻器。

關鍵字

吉伯特混頻器 ； 交叉耦合對 ； 主動負載 ； 電阻回授反向緩衝放大器 ； 阻抗轉換放大器 ； 高電壓轉換增益

並列摘要

In this thesis, a down-conversion mixer for heart beat and respiration monitoring radar is designed by using the Gilbert cell structure with active loads. Monitoring the signals in our life by electromagnetic wave is one of the goals which people have worked hard to achieve. For non-contact heart beat and respiration monitoring, Doppler radar is one of the most popular approaches in this domain in recent years.
This thesis starts from introducing the heart beat and respiration monitoring radar, and then analyses the role of mixers in these radars and different structures of mixers. The Gilbert cell is the most popular structure in active mixers and there are many papers proposed different methods to improve the performance of Gilbert cell mixer.
This thesis proposes a new structure of Gilbert cell mixer which contains cross-coupled pair active loads. This new structure can enhance the transconductance of the RF MOSFET and the impedance of outputs without increasing the voltage drop at the output loads. And the conversion gain can also be effectively improved. To avoid the possibility of circuit oscillation, the resistor feedback inverter topology transimpedance amplifiers are added to the structure.
In this thesis, a Gilbert cell mixer with active loads is developed in TSMC 0.18μm CMOS technology at 24GHz and simulated by the ADS and Sonnet. The chips are measured in National Chip Implementation Center with high frequency measurement instrument to prove that this new structure can effectively improve the properties of Gilbert cell mixer.

並列關鍵字

Gilbert cell mixer ； cross-couple pair ； active load ； resistor feedback inverter topology transimpedance amplifiers ； high voltage conversion gain

參考文獻

[1] Jri Lee, Yenlin Huang, Y. Chen, Hsinchia Lu, and Chiajung Chang, "A low-power fully integrated 60GHz transceiver system with OOK modulation and on-board antenna assembly," in International Solid-State Circuits Conference, pp. 316-317, Feb. 2009.

[2] Jri Lee, Yi-An Li, Meng-Hsiung Hung, and Shih-Jou Huang, "A fully-integrated 77-GHz FMCW radar transceiver in 65-nm CMOS technology," IEEE Journal of Solid-State Circuits, vol. 45, no. 12, pp. 2746 - 2756, Dec. 2010.

[3] J.C. Lin, "Noninvasive microwave measurement of respiration," Proceedings of the IEEE, vol. 63, no. 10, pp. 1530, Oct. 1975.

[4] J.C. Lin, "Microwave sensing of physiological movement and volume change: A review," Bioelectromagnetics, vol. 13, no. 6, pp. 557-565, Jan 1992.

[5] Hsuan-Wei Yeh, “FMCW and monopulse radar for heart beat and respiration monitoring,” Graduate Institute of Electronics Engineering Master Thesis, National Taiwan University, July 2013.