應用於Wireless LAN之Mixer與VCO之研製

臺灣的無線通訊系統，發展至今已漸成熟，而針對無線通訊產品的小體積、低消耗功率、低成本與高整合性，目前大多以CMOS技術為主要。本篇論文中，以低消耗功率壓控振盪(VCO)與低消耗功率的混頻器(Mixer)的設計為主要方針。在壓控振盪器(VCO)電路設計的架構，採用電流再使用式的架構，配合另一端的ＬＣ共振腔設計完成，並且也設法改善了此架構差動輸出波形不對稱的缺點。為了改善輸出波形不對稱的缺點，使NMOS與PMOS的電子漂移率達到相同，以調整MOS退化電阻的觀念改善輸出波形不對稱的問題。另外也有嘗試外加一組mos切換電容與一組mos切換電感的電路架構，符合Wimax頻段。本論文中針對2.4 GHz與5.2GHz兩個符合WLAN頻段規範的壓控振盪器，以及切換式寬頻的壓控振盪器有多方面的研究設計。混頻器(Mixer)電路設計架構，使用低電壓全差動褶疊式混頻器架構，我們是利用本地振盪訊號(LO)頻率的輸入做為電路訊號的切換，與RF端電路採用並接的方式達到混頻的效果，可以利用摺疊架構的動作來達到低電壓操作模式，輸出也因為疊接的MOS減少，因而增大輸出振幅的電壓輸出。在參考的文獻中可以得知，理論上全差動式架構RF訊號與LO訊號並不會在中頻的輸出端出現，所以有較佳隔離度的表現。本論文中針對5.2GHz符合WLAN頻段規範的低電壓混頻器有多方面的研究設計。

關鍵字

電流再使用式壓控振盪器；摺疊式混頻器

並列摘要

In recent years, the application products of the wireless local network have already been used extensively on the market. The wireless products with the smaller size, lower power consumption, lower cost and high integration are the major stream of the current market. Hence, it has become an inevitable trend to use the CMOS technologies to implement the RF transceivers. The newly proposed VCO uses both NMOS and PMOS transistors in the ross-connected pair as a negative conductance generator [22]. The series stack of N- and PMOSFETs allows the supply current to be reduced by half that of the conventional LC-VCO while providing the same negative conductance. This topology is prone to have differential output signals which are not fully differential. Another composition, we used mos switch capacitance and inductance, which to come to a broad band turning range . The basis of mixing relies on the multiplication of two signals, we will assume an ideal square wave, the LO signal and an incoming information signal, the RF signal. The voltage of the RF signal is amplified and converted into a current by a driver stage. The LO signal is used to steer all of the current from one transistor to the other at the LO switching stage. To use the symmetrical and folded construction, the proposed Mixer can work by lower voltage and the active balum can help us to simply measure.

並列關鍵字

current reused vco ； folded mixer

參考文獻

[4] Ali Hajimiri, and Thomas H. Lee ,“A General Theory of Phase Noise in Electrical Oscillators.”, IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 33, NO. 2, FEBRUARY 1998

[5] Razavi, B. “A study of phase noise in CMOS oscillators,” IEEE Journal of Solid-State Circuits , Iss.3, Mar 1996 Pages:331-343

[6] Ulrich L. Rohde., “Microwave and wireless synthesizers :theory and design,” Wiley,c1997.

[8] Ali Hajimiri, and Thomas H. Lee ,“A General Theory of Phase Noise in Electrical Oscillators.”, IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 33, NO. 2, FEBRUARY 1998

[9] 朱元凱，“應用於802.11a WLAN 之5GHz U-NII 頻帶降頻器CMOS RFIC”，國立成功大學電機工程學系，2002

國際替代計量

應用於Wireless LAN之Mixer與VCO之研製

未授權

主題瀏覽