具四埠功率結合技術的CMOS功率放大器之研究

Abstract

本篇論文主題在於探討以矽製程來設計的全積體化之功率放大器電路，應用於IEEE-802.11a 5.8-GHz的通訊系統頻帶。採用台積電0.18μm互補金屬氧化半導體製程。本篇論文提出兩種類型的功率結合器之設計，基於此功率結合概念，可以有效率改善矽製程條件上的限制。 針對第一類型，在此我們提出一個具有四埠變壓器耦合功率局結合技術的功率合成器。藉由單埠變壓器部分，主側線圈以全厚金屬結構，可以解決直流電流密度在矽製程上的限制。高頻部分，在次側線圈利用部分多層金屬結構可以有效提升邊緣功率耦合效率，進而達到瓦特級的輸出規範。 第二類型，在此我們提出一個具有四埠阻抗轉換變壓器。針對四埠差動放大器的輸入阻抗匹配，我們採用分散式主動變壓器設計概念。在四埠阻抗轉換變壓器部分，利用最上層金屬高品質特性做為佈局的金屬走線。高頻部分，有效率改變金屬走線的線寬與單埠變壓器中心點直接接地，進而達成在輸入單埠側和輸出的四埠差動放大器之間的阻抗匹配。 最後為了實現高效率和全積體化的功率放大器，如何有效率的提高在四埠差動功率放大器與功率結合器之間的匹配性，此部分設計概念將於第四章節詳細論述。

The thesis investigated the analysis, design and implementation of a fully integrated circuit of power amplifier with silicon-based technologies, application to the family of IEEE-802.11a and 5.8-GHz bandwidth on the communication system. This paper proposes two type designs of power combiner, based on the conception of power combination; it can be efficiently to improvement limitation on silicon processes. For the first topic, the technique which we provide a power combiner with a four-ports transformer-coupled is presented here. By the single port of transformer, we introduce the stack structure with metal layers. On primary-side is the structure with all-stack metal layers, which solves the limitation of dc current density based on silicon processes. In part of high frequency, the secondary-side structure with segment stack metal layers can be efficiently to improve the edge-coupled efficiency, and proceed to reach the watt-level of power specification. Second topic, we demonstrate a four-ports impedance transformation transformer III here. For the input impedance match of four-ports differential amplifier, we used a design conception with distributed-active-transformer. The part of four-ports impedance transformation transformer employ the top metal possessed high quality characteristic for layout with metal line. In part of high frequency, it efficiently to change the width of metal line and mid-point with single port transformer is directly ground connection, and proceeds to reach impedance match between the input single-side and the input of four-ports differential amplifier. Finally, to reach a high efficiency and fully integrated power amplifier, how to improve the match between the four-ports differential amplifier and output power combiner efficiently is described in detail in the chapter-4.