應用於第五代行動通訊系統之低雜訊放大器及寬頻雙向分佈式放大器

Abstract

放大器在無線收發機中扮演著重要的腳色。在5G和高數據速率應用的時代，對高效且高性能放大器的需求日益增加。隨著第五代行動通訊的蓬勃發展，毫米波的研究與應用已成為當今的主要趨勢。然而，隨著對更高頻寬和更快傳輸速率的需求不斷增長，目前的無線通訊頻率主要在6 GHz以下已經相當飽和。因此，往更高頻率的設計已成為技術發展中的關鍵方向。其中，Ka-band被視為第五代行動通訊的主要潛在發展頻段。在無線通訊系統中，發射機的設計至關重要，而本論文的主要焦點在於對放大器的設計和進行研究。 本篇論文主要分成兩個部分: 第一部分為利用90-nm CMOS所設計的雙向分佈式放大器的研究。雙向放大器對收發系統面積的縮減有幫助，藉由電路的架構選擇讓電路可以有寬頻的特性和共用匹配電路。此雙向分佈式放大器從1.9到33.5 GHz的3 dB頻寬，並且有13.8 dB的增益，還有著2.9 dB的雜訊指數。因此，它是用於高速數據傳輸的系統。 第二部分設計了3個以0.18 μm GaAs pHEMT製程所設計的Ka-band低雜訊放大器，其中設計頻段為5G可行通訊頻段。第一個低雜訊放大器利用電容匹配的設計有著19.4到32.1 GHz的3 dB頻寬，還有23 dB的增益，與1.5 dB的雜訊指數。第二個低雜訊放大器利用傳輸線匹配的設計有著22.9到32.9 GHz的3 dB頻寬，還有21.5 dB的增益，與1.8 dB的雜訊指數。第三個低雜訊放大器利用Cascode的架構設計有著21.3到34 GHz的3 dB頻寬，還有15.9 dB的增益，與2.2 dB的雜訊指數。

Amplifiers play a crucial role in wireless transceivers. The demand for efficient and high-performance amplifiers is increasing in the area of 5G and high-data-rate applications. The booming growth of fifth-generation mobile communication (5G) has made millimeter-wave research and applications an important trend. However, as the demand for higher bandwidth and faster transmission rates continues to grow, the current wireless communication frequencies, primarily below 6 GHz, are becoming saturated. Therefore, designing for higher frequencies has become a key direction in technological development. Among these, the Ka-band is considered a primary potential development frequency band for 5G. In wireless communication systems, the design of the transmitter is crucial, and this thesis focuses primarily on the design and study of amplifiers. This thesis is primarily divided into two parts. The first part focuses on the study of a bidirectional distributed amplifier using 90-nm CMOS process. Bidirectional amplifiers contribute to the reduction of the overall system area by employing a circuit structure that enables broadband characteristics and shared matching circuits. This bidirectional distributed amplifier achieves a 3 dB bandwidth from 1.9 to 33.5 GHz, with a gain of 13.8 dB and a noise figure of 2.9 dB. Therefore, it is suitable for systems requiring high-speed data transmission. The second part involves the design of three Ka-band low noise amplifiers (LNAs) using the 0.18 μm GaAs pHEMT process, targeting the communication frequencies for 5G. The first LNA, employing capacitor matching, achieves a 3 dB bandwidth from 19.4 to 32.1 GHz, with a gain of 23 dB and a noise figure of 1.5 dB. The second LNA, utilizing transmission line matching, achieves a 3 dB bandwidth from 22.9 to 32.9 GHz, with a gain of 21.5 dB and a noise figure of 1.8 dB. The third LNA, designed with a Cascode architecture, achieves a 3 dB bandwidth from 21.3 to 34 GHz, with a gain of 15.9 dB and a noise figure of 2.2 dB.