功率負載量測技術於射頻功率放大器之應用

The Power Loadpull Technique for the Implementation of RF Power Amplifier

涂志和(Chih-Ho Tu)

指導教授 ： 林明權

崑山科技大學/工程學院/電子工程研究所/碩士(2004年)

摘要

本論文主要內容在於利用負載功率量測系統(Load Pull System)來探討Power Cell之特性結果，並利用其量測結果及設計射頻功率放大器的基本原理，和電路設計技巧來設計一個符合802.11a標準之5.2GHz頻帶的A類射頻功率放大器，再以負載功率量測系統來驗證其相關設計理論。文中利用Agilent ADS (Advance Design System)2003a及Ansofa Designer模擬軟體，
和台灣本地之半導體製程公司(GCTC)所提供之InGa/GaAs HBT電晶體、電感及電容模型進行模擬、分析及設計。
我們藉由模擬的方式設計完成一個操作電壓為DC 3.3V、5.2GHz頻帶的A類射頻功率放大器，其P1dB點之功率增益為12.63 dB、輸出功率為23.2
dBm，並探討不同ballast電阻值與不同的Layout排列方式對Power Cell之特性及大電流時熱效應之影響，進而將其Power Cell之量測數據及Layout排列方式應用於電路設計中，完成單晶微波積體電路(MMIC)之製作。

關鍵字

射頻功率放大器 ； 負載功率量測系統 ； 熱效應 ； 單晶微波積體電路

並列摘要

In this thesis, using Maury Microwave's automated load pull system to perform load and source pull measurement to obtain the power characterization of the power cell, and then these characteristics are investigated. Furthermore, based on measured results of the power cell and the theory of RF power amplifier (PA), a 5.2 GHz GaAs HBT PA specified by IEEE 802.11a Wireless LAN has been proposed, designed, and simulated. Using simulation tool, Agilent EEsof ADS (Advance Design System)2003a and Ansofa EEsof Designer, with the models of InGaP/GaAs Power HBT, resistor, capacitance, and inductance provided by GCTC(Global Communication Technology Corporation) to simulate and analyze proposed circuits.
According to simulation results, power gain of 12.63 dB, 1 dB compression output power (OP1dB) of 23.2dBm can be achieved by the PA with 3.3V supply voltage at the center frequency of 5.2 GHz. In addition, power cells with various values of ballasting resistors and different sub-cells layout arrangements to reduce the thermal effect on power cells also have been discussed, and then the suitable layout of the power cell will be applied in the monolithic microwave integrated circuit (MMIC) PA design.

並列關鍵字

RF power amplifier ； MMIC ； load pull system ； the thermal effect

參考文獻

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[4] Y. Takayama: “ A new load-pull characterization method for microwave power transistors”, NEC Research & Development, No. 50, pp. 23-29(July 1978) also in 1976 IEEE MTT-S Int.Microwave Symp., Digest, Tech. Paper. 218-220(1976)

[5] Pei-Der Tseng, Liyang Zhang, Guang-Bo Gao, M. Frank Chang: “A 3-V Monolithic SiGe HBT Power Amplifier for Dual-Mode (CDMA/AMPS) Cellular HandsetApplications”, IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL.35, NO. 9, SEPTEMBER 2000

[6] MAURY Microwave “ ATS Training seminar”，November 2001