無線區域網路之CMOS鏡像拒斥低雜訊放大器、超寬頻系統之電流再利用低雜訊放大器、超寬頻系統之低功率高線性度無電感混頻器之設計與研究

Abstract

本論文的第一部份探討具有鏡像拒斥功能之低功率低雜訊放大器應用於IEEE 802.11a，此電路設計一並聯電感電容槽於電流再利用架構的內部級來達成鏡像拒斥的功能，鏡像拒斥濾波器的原理及品質因數Q強化技巧將被分析與介紹，量測結果顯示此電路擁有令人滿意的效能與-27 dB的鏡像拒斥能力。 在第二部份中將提出一超寬頻低雜訊放大器，此電路改善電阻並聯回授放大器，將其電阻負載用PMOS替代。藉由堆疊兩顆電晶體並在其閘級與汲級間加入回授電阻，此超寬頻低雜訊放大器能夠同時達到高增益與輸入端寬頻匹配，量測結果顯示：優於-10 dB之輸入與輸出端反射損耗、3.3 dB之最小雜訊指數、14.1 dB之平均增益並消耗14.4 mW之功率。 最後部份提出一低功率、高線性度、無電感混頻器應用於超寬頻通訊系統，此混頻器利用共閘級放大器作為轉導級，使之較易達到寬頻輸入端匹配且不需要電感，一些線性度改善技巧將被利用來增加IIP3，量測結果顯示：在3.1到10.6 GHz頻段其射頻端反射損耗大於-10 dB，在100 MHz中頻端反射損耗為-26 dB，且達到3到8 dBm之高線性度與4.68 mW之低功率消耗。

In the first part of this thesis, a low-power low-noise amplifier (LNA) with image-rejection (IR) function is designed for IEEE 802.11a. It exploits a simple parallel LC tank in inter-stage of current-reused configuration to achieve IR function. The principles of IR filter will be analyzed and quality factor Q enhancement technique will be introduced. The measured results show the satisfied performances and IR ability of -27 dB. In the second part, an ultra-wideband (UWB) LNA is proposed. It improves resistive shunt feedback amplifier to replace load resistor by a PMOS. By stacking two transistors and employing a feedback resistor to connect gate and drain, the proposed LNA can simultaneously achieve high gain and input impedance matching. The measured results reveal better than -10 dB input and output return loss, minimum noise figure of 3.3 dB, and average gain of 14.1 dB from consuming 14.4 mW power. Finally, a low-power, high-linearity, and inductorless mixer for UWB communication is presented. The mixer adopts common-gate amplifier as transconductance stage to easily achieve wideband matching without inductors. Some linearity-improvement techniques are exploited to increase the IIP3. The measured results express better than -10 dB RF port return loss in 3.1-10.6 GHz, IF port return loss of -26 dB at 100 MHz, high IIP3 of 3~8 dBm, and low power consumption of 4.68 mW.