超寬頻通訊系統之降頻混頻器的設計與實現

Abstract

本篇論文介紹了無線通訊系統中常用的射頻接收機系統架構及混頻器的參數介紹外，並藉由ABIDI於2000年所提出CMOS混頻器之雜訊模型，透過此模型將使電路設計者更清楚的了解到雜訊源將經由何種過程出現在混頻器的輸出端。另外，由於無線通訊系統的進步下，窄頻通訊系統已不符合時代潮流的需求，因此我們將研究如何修正及改良傳統的吉伯特混頻器，以符合未來之超寬頻無線通訊系統規格之要求。 由於CMOS製程在成本上佔有絕對的優勢，且具有極佳的系統整合能力，因此本論文以tsmc 0.18um 1P6M CMOS製程來實作1.5-2.5 GHz多規格之無線通訊的應用，以及符合3.1-10.6 GHz超寬頻無線通訊系統之頻段。由於tsmc提供了不錯的RF Model及ADS Design Kits，透過良好的設計及縝密的佈局後，在10 GHz以內均可能到相當平坦的轉換增益及良好的隔離度。最後，在考量到整體功率消耗及晶片面積下，採用微混頻器的設計理念下，將電路加以改良，並設計出以電阻匹配的超寬頻降頻微混頻器。

In this thesis, we introduce RF transceiver architectures for the wireless communication system and some parameters of the down-conversion mixer. By means of the noise model of RF-CMOS mixers presented by ABIDI in 2000, circuit designers will know how the noise appears at the output of a CMOS down-conversion mixer. Besides, due to the progress of the wireless communication system, narrow band system does not meet the need of the trend. The thesis shows how to improve and revise the conventional Gilbert Cell mixer to meet the spec for UWB applications. Complementary Metal Oxide Semiconductor(CMOS) would be the most suitable technology for the wireless communication, attributed to its lower cost ,lower power and higher level of integration with baseband circuits. We implement 1.5-2.5 GHz multi-standard wireless applications and 3.1-10.6 GHz UWB application. Because of the stable RF model and accurate ADS Design Kits provided by tsmc, we get the measurement results with a flat conversion gain and good isolation. Moreover, under consideration of the power consumption and the chip area, we improve our architecture with input matching using resistive elements and finally design an ultra-wideband down-conversion mixer