超寬頻系統射頻關鍵模組之研製

Design of RF Key Modules for Ultra-wideband System

羅育聰(Yu-Tsung Lo)

指導教授 ： 江簡富

國立臺灣大學/電機資訊學院/電信工程學研究所/碩士(2009年)

https://doi.org/10.6342/NTU.2009.02069

摘要

在本篇論文中，我們利用標準TSMC 0.18 μm CMOS製程設計超寬頻的低雜訊放大器(LNA)、射頻前端(RF-frontend)以及單旁波混頻器(SSB-mixer)。
我們提出了一個新的寬頻低雜訊放大器的設計方法，適用於共閘極(CG)共源極(CG)串接放大器。新的設計方法源自於找出了共閘極和共源極間的匹配關係。此外，新的設計流程大幅簡化了設計複雜度並且解釋了此一架構能夠同時達到增益和雜訊的平坦響應。我們所設計出的寬頻低雜訊放大器具有良好的增益，輸入匹配以及低雜訊指數。在3.1-10.3 GHz的頻寬內，量測出的雜訊指數為2.5-3.9 dB，功率消耗為13 毫瓦。ㄧ個單平衡式混頻器(single-balanced mixer)被設計要整合在LNA後方，因為是採用直接降頻式(direct conversion)接收機，混頻器經過匹配設計後直接接在低雜訊放大器後，模擬的射頻前端conversion gain為19 dB，增益的平坦度在正負0.5 dB以內，總共的功率消耗為 24 毫瓦。
在本地振盪電路方面，MB-OFDM UWB系統需要快速的切頻速度，所需的14
個頻率需利用單旁波混頻器(SSB-mixer)從固定頻率的鎖相迴路裡產生，並配合適當
的切頻方式。本論文設計的SSB-mixer使用其中兩個mixer cell對其輸出做相加或相減的的動作以選到output的upper sideband或lower sideband。而傳統的single　sideband mixer是選擇進入mixer cell的訊號為同相位或正交相位來決定輸出的旁波。

關鍵字

超寬頻 ； 低雜訊放大器 ； 混頻器 ； 射頻前端

並列摘要

This thesis proposes a UWB low-noise amplifier (LNA), a UWB RF front-end, and a singlesideband
mixer for mode-1 MB-OFDM UWB system. All three components are designed in
TSMC 0.18 μm RF mixed signal CMOS process. The measured results of LNA chip features
2.5 dB to 3.9 dB noise figure (NF) from 3.1 GHz to 10.3 GHz at the power consumption of 13
mW. A wideband design technique for common-gate to common-source cascaded LNA is also
proposed. The technique greatly simplifies the design of wideband LNA and also enhances
flat response of gain and noise figure (NF). A single-balanced mixer following the LNA is
designed to form a UWB RF front-end, which shows a simulation conversion gain of 19 dB
with gain variation less than 1 dB. Total power consumption of the UWB RF-frondend is 24
mW. In the LO circuitry of MB-OFDM system, fast switching time is required and it can
only be achieved by direct-signal generating. Single-sideband (SSB) mixer is then required to
generate the desired 14 tones of MB-OFDM UWB from a single locked tone. The proposed
SSB mixer features the sideband selection at the output stage of the mixer instead of LO
routing as the conventional design.

並列關鍵字

Ultra-wideband ； LNA ； mixer ； RF front-end

參考文獻

[1] A. Batra et al., Multi-band OFDM physical layer proposal for IEEE 802.15 Task Group

[2] A. Batra, J. Balakrishnan, G. R. Aiello, J. R. Foerster,, A. Dabak, ”Design of a multiband

OFDM system for realistic UWB channel environments,” IEEE Trans. Microwave

[3] J. A. C. Bingham, ”Multicarrier modulation for data transmission: An idea whose time

has come,” IEEE Commun. Mag., vol. 28, pp. 5-14, May 1990.