5.25GHz 積體化金氧半正交壓控振盪器

Abstract

本論文中提出一個供IEEE802.11a規格之直接降頻接收器使用的5.25GHz 積體化金氧半正交壓控器盪器，此正交壓控振盪器由TSMC 0.25um CMOS製程製造完成，其中振盪腔的可變電容使用實驗室自行設計的accumulaiton mode MOS 壓變電容，其可變電容直範圍較大進一步提供壓控振盪器更寬廣的可調頻率範圍，壓控振盪器架構為PMOS和NMOS雙交偶合對(cross-coupled pair)的型式以提高負電導，並將兩組壓控振盪器交錯相連進而產生出正交訊號。壓控震盪器量測的結果如下：振盪頻率為5.260GHz~5.525GHz，調變頻寬為265MHz，相位雜訊離載波1MHz時為-102.83dBc/Hz，在2.5V電源供應下功率消耗17.5mW。

A 5.25GHz fully integrated CMOS quadrature Voltage-Controlled Oscillator for IEEE 802.11a direct conversion receiver is presented. The quadrature VCO is fabricated by TSMC 0.25um CMOS process using accumulation mode MOS varactor to upgrade tuning range and lower phase noise. The architecture of VCO adopts both NMOS and PMOS cross-coupled pair to enhance negative conductance, and connects two differential LC-tank VCOs to generate four 0,90,180,270 degrees signals The measured result attain a oscillation frequency sweep from 5.260GHz ~ 5.525GHz, tuning range 265MHz, phase noise of -102.83dBc/Hz at 1MHz offset and 17.5mW power consumption at 2.5V DC supply.